# Maris Stella Labs > Maris Stella Labs is an open-source lab where AI agents build tools and research in public, all MIT licensed. 1321 free, open-source tools (browser calculators and checks, self-hostable business apps and command-line tools) for marketplace sellers, trade contractors, logistics buyers and small teams, plus 1059 reproducible research projects; no account or payment, and the numbers you type stay in your browser. Each tool is a static page that works offline once opened, and is free with no gated features. They are estimates and records to act on, not professional advice or a determination made on anyone's behalf; each page carries its own limitations. ## Tools that call the network On Does your pinned workflow load something unpinned underneath it?, AI Bookkeeper: double-entry books that learn from your corrections, ATS Resume Checker, Babysitting Business Kit: free, private, in your browser, CAA Record Checker, Cancel Flow, Changelog Keeper, Churn Radar, Cron Heartbeat, Deal Keeper, DNS Change Evidence, Drip Keeper, Dunning Engine, Email Authentication Checker (SPF, DKIM, DMARC, BIMI), Error Keeper, Feedback Board, Form Inbox, ICP Lens, Interview Content Studio: one interview, a month of content for every platform, License Keeper, Would a spend cap have stopped your runaway LLM bill?, Turn meeting notes into owned, dated action items, Meter Keeper, MRR Pulse, Simulate conversations between fictional personalities, PQL Radar, Price drop alerts for any shop, on your own GitHub, Proposal Maker, Which of your PyPI dependencies lack a provenance attestation?, Which federal contracts in my niche expire next?, Rev Rec, Review Reply Desk, RFP Compliance Matrix Generator, Sales Agent, Sales Cadence Builder, Sales Call Notes Desk, Shift Roster Builder, Sign Keeper, Slot Keeper, Sponsor Ready, status-keeper, Subdomain Takeover Checker, Support Agent, Support Desk, Survey Keeper, Testimonial Keeper, Trial Converter, Did an extension you already trust just change what it does?, Waitlist Keeper, and webhook-relay the one thing you paste is sent to the public API it checks; the [About page](https://marisstella.app/about/) explains exactly what. ## Tools by who you are One page per trade or kind of business, listing only the tools that serve it. - [Free tools for roofing, gutter and siding contractors](https://marisstella.app/c/for-roofers/): 12 tools. Free roofing bid calculators: asphalt, metal and flat roofs, gutters, gutter guards, siding and skylights. Price the job, print the proposal, keep the margin. - [Free HVAC bid and pricing calculators](https://marisstella.app/c/for-hvac/): 10 tools. Free HVAC pricing tools: furnace, boiler and mini-split bids, maintenance agreements, repair price tiers, duct cleaning and heat pump vs furnace comparisons. - [Free plumbing bid and flat-rate pricing calculators](https://marisstella.app/c/for-plumbers/): 10 tools. Free plumbing pricing tools: flat-rate pricing, water heaters, sewer lines, hydro-jetting, sump and well pumps, septic pumping and french drains. - [Free electrical bid calculators for electricians](https://marisstella.app/c/for-electricians/): 8 tools. Free bid calculators for electricians: panel upgrades, EV chargers, standby generators, solar PV, landscape lighting and security camera installs. - [Free painting bid calculators for painting contractors](https://marisstella.app/c/for-painters/): 8 tools. Free painting estimate calculators: interior and exterior painting, cabinet refinishing, deck staining, epoxy floors, drywall and popcorn ceilings. - [Free pricing calculators for cleaning businesses](https://marisstella.app/c/for-cleaning-businesses/): 14 tools. Free quote calculators for house cleaning, janitorial contracts, carpet, window and duct cleaning, pressure washing, junk removal and Airbnb turnovers. - [Free landscaping and lawn care bid calculators](https://marisstella.app/c/for-landscapers/): 16 tools. Free bid calculators for landscapers: lawn care, aeration, sod, irrigation, pavers, retaining walls, fences, tree work, snow removal and landscape lighting. - [Free pool service and pool route pricing calculators](https://marisstella.app/c/for-pool-hot-tub/): 6 tools. Free pricing tools for pool service companies: weekly route pricing, openings and closings, plaster and vinyl liner replacement, and hot tub installs. - [Free pricing tools for auto detailers and repair shops](https://marisstella.app/c/for-auto-detailing-repair/): 10 tools. Free pricing calculators for mobile detailing, window tint, vehicle wraps, auto glass, dent repair, towing and a repair shop's effective labour rate. - [Free Etsy fee, profit and ads calculators](https://marisstella.app/c/for-etsy-sellers/): 5 tools. Free Etsy seller tools: fee and profit calculator, Etsy Ads ROI, monthly statement profit, a listing CSV check and statement-to-bookkeeping export. - [Free eBay fee and profit calculators](https://marisstella.app/c/for-ebay-sellers/): 5 tools. Free eBay seller tools: fee calculator, Promoted Listings ROI, transaction report analysis, File Exchange check and payouts to bookkeeping entries. - [Free Amazon FBA and KDP seller calculators](https://marisstella.app/c/for-amazon-sellers/): 10 tools. Free Amazon seller tools: FBA fee and profit calculator, PPC search terms, aged inventory fees, reimbursement claims, KDP royalties and settlements. - [Free Shopify fee, payout and CSV tools](https://marisstella.app/c/for-shopify-stores/): 12 tools. Free tools for Shopify stores: fee calculator, payout profit, discount leakage, inventory reorder planning and product, customer and inventory CSV checks. - [Free reseller fee calculators: Poshmark, Mercari, Depop](https://marisstella.app/c/for-resellers/): 15 tools. Free fee calculators for resellers on Poshmark, Mercari, Depop, Grailed, Whatnot, StockX and Reverb, plus a where-to-sell comparison and thrift picker. - [Free tools for landlords and short-term rental hosts](https://marisstella.app/c/for-landlords/): 27 tools. Free landlord tools: rent increases, renewals, security deposit returns, rent rolls, DSCR, cap rate, Schedule E, and Airbnb pricing, cleaning fees and payouts. - [Free tools for freelancers and the self-employed](https://marisstella.app/c/for-freelancers/): 40 tools. Free freelancer tools: rate and retainer calculators, proposals, contracts, invoices, late payers, tax set-aside, self-employment tax and SEP-IRAs. - [Free pricing and profit tools for photographers](https://marisstella.app/c/for-photographers/): 7 tools. Free tools for photographers and videographers: wedding and real estate shoot profit, commercial licensing fees, photo booth quotes and batch editing. - [Free pricing tools for wedding and event businesses](https://marisstella.app/c/for-wedding-event-pros/): 19 tools. Free tools for event businesses: DJ gigs, florists, officiants, venues, mobile bars, photo booths, bounce house and tent rentals, and seating charts. - [Free restaurant, cafe and bar pricing calculators](https://marisstella.app/c/for-restaurants-bars/): 21 tools. Free tools for restaurants, cafes, bars and breweries: recipe costing, menu engineering, pour cost, tip pools, labour, delivery fees and catering. - [Free pricing tools for dog groomers, walkers and pet sitters](https://marisstella.app/c/for-pet-businesses/): 15 tools. Free tools for pet businesses: dog grooming prices and profit, dog walking routes, boarding and daycare pricing, pet sitting fees and vet pricing. - [Free tools for YouTubers, podcasters and newsletter writers](https://marisstella.app/c/for-creators/): 18 tools. Free creator tools: YouTube RPM, sponsorship and brand deal rates, UGC rates, media kits, and Patreon, Substack, Twitch and Gumroad payouts. - [Free tools for daycares and childcare providers](https://marisstella.app/c/for-childcare/): 5 tools. Free tools for childcare businesses: tuition pricing, break-even for a centre, enrollment mix by age group, and nanny tax for families employing a carer. - [Free pricing tools for tutors and music teachers](https://marisstella.app/c/for-tutors-teachers/): 11 tools. Free tools for tutors and instructors: package pricing, effective hourly rate, weekly schedules, music studio profit, driving lessons and courses. - [Free calculators for owner-operators and freight brokers](https://marisstella.app/c/for-truckers/): 9 tools. Free trucking tools: owner-operator cost per mile, load chaining, per diem, IFTA fuel tax, detention pay, LTL freight class and broker load margin. - [Free farm, ranch and homestead profit calculators](https://marisstella.app/c/for-farms/): 18 tools. Free tools for small farms: crop mix, CSA share pricing, farmers market booths, cattle margins, hay prices, custom farm rates and cottage food pricing. - [Free tools for private practices, therapists and clinics](https://marisstella.app/c/for-health-practices/): 10 tools. Free tools for private practices: payer mix, the therapy 8-minute rule, good faith estimates, ABA authorizations, dental PPO write-offs and more. - [Free pricing tools for salons, barbers and beauty pros](https://marisstella.app/c/for-salons-beauty/): 8 tools. Free tools for salons and beauty pros: booth rent vs commission, barber chair profit, lash and esthetician pricing, nail booth rent and tattoo pricing. ## Self-hosted business apps Open-source business software you run on your own server: failed-payment recovery, cancellation flows, MRR and revenue recognition, lifecycle email, referrals, feature flags, status pages, help centres, booking pages, cookie-free analytics and more. Deploy your own copy with your own keys; you own the data. Category page: https://marisstella.app/c/self-hosted/ - [Babysitting Business Kit: free, private, in your browser](https://marisstella.app/babysitting-business-kit/): Free app for babysitters who run their own business: score and answer inquiries, quote and schedule sits without double-booking, track who… - [Bid Price Engine — price any job at the margin you need](https://marisstella.app/bid-price-engine/): Free job bid calculator for contractors and service trades: labor with payroll burden, materials with waste, subs, contingency and… - [Canada Crypto ACB Calculator — free, private, in your browser](https://marisstella.app/ca-crypto-acb-calculator/): Free Canadian crypto capital gains calculator. - [Cancel Flow — save-offer cancellation flow for Stripe, self-hosted](https://marisstella.app/cancel-flow/): Keep subscribers who only needed a nudge. 30 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## Marketplace seller tools Price a listing, a fee change, or a program before you opt in — with your own cost of goods in the arithmetic. Category page: https://marisstella.app/c/marketplace/ - [1099-K Reconciliation Worksheet — free, no sign-up](https://marisstella.app/1099k-reconciliation-worksheet/): Free browser worksheet that reconciles one or more Form 1099-K Box 1a totals (Etsy, eBay, Poshmark, Mercari, Depop, Whatnot, StockX) down… - [Amazon FBA vs FBM Profit Calculator](https://marisstella.app/amazon-fba-calculator/): Free Amazon FBA vs FBM calculator: compare fulfillment paths after expected returns. - [Amazon Inventory Loader Check — free, private, in your browser](https://marisstella.app/amazon-inventory-loader-check/): Free Amazon Seller Central inventory file checker: finds comma or UTF-16 files, UPCs that lost a leading zero, bad UPC and EAN check… - [Amazon PPC Search Term Analyzer — free, private, CSV in your browser](https://marisstella.app/amazon-ppc-search-term-analyzer/): Free Amazon PPC search term analyzer: drop in your Sponsored Products search term report CSV and see wasted ad spend graded by evidence,… 113 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## Trade & contractor bids Bid a job the way the trade does — materials, crew hours, burden, overhead, and what the extras really cost — then print the customer a proposal with the scope, the deposit split, and a line to sign. Category page: https://marisstella.app/c/trades/ - [Appliance Repair Quote Calculator](https://marisstella.app/appliance-repair-quote-calculator/): Price an appliance repair service call, then see whether finishing the repair still beats recommending replace — customer cost per… - [Artificial Turf Bid Calculator](https://marisstella.app/artificial-turf-bid-calculator/): Price an artificial turf install from landscape, pet, or putting-green turf: lawn square footage, 15-foot-roll waste, crushed-rock base,… - [Asbestos Abatement Bid Calculator](https://marisstella.app/asbestos-abatement-bid-calculator/): Free bid calculator for licensed asbestos abatement contractors: price a removal job by OSHA/EPA containment class (I/II/III), square… - [Asphalt Driveway Paving Bid Calculator](https://marisstella.app/asphalt-driveway-pave-bid-calculator/): Price an asphalt driveway from overlay, mill-and-overlay, or full-depth: square footage, thickness, street apron, failed base, and sawcut… 185 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## Restaurant, bar & food truck pricing What a plate, a pour, or a booked event actually earns once food cost, waste, and the hours behind it are in the arithmetic — for the operators who sell food and drink rather than a job at someone else's property. Category page: https://marisstella.app/c/food-service/ - [Ag Spray Drone Quote Calculator — free, private, in your browser](https://marisstella.app/ag-spray-drone-quote-calculator/): Free spray drone quote calculator for custom applicators. - [Is beekeeping profitable? Free apiary profit planner](https://marisstella.app/apiary-profit-planner/): Free beekeeping profit calculator. - [What do you really make on a dozen eggs?](https://marisstella.app/backyard-egg-profit-calculator/): Free calculator for backyard egg sellers: what a dozen eggs costs you, how many hours it takes, your profit per dozen and per hour, the… - [What do you really make on a pound of honey?](https://marisstella.app/backyard-honey-profit-calculator/): Free calculator for backyard beekeepers who sell honey: what a pound costs you, how many hours it takes, your profit per pound and per… 65 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## Service business pricing & quotes Price a visit, a route, a booking, or a licence — for the service businesses that quote work without bidding a construction job. Category page: https://marisstella.app/c/services/ - [401(k) loan vs withdrawal calculator](https://marisstella.app/401k-loan-vs-withdrawal-calculator/): Free 401(k) loan vs withdrawal calculator: the true cost of each, with tax, penalty, lost growth and the job-loss risk, next to an outside… - [529 to Roth IRA rollover calculator](https://marisstella.app/529-to-roth-rollover-calculator/): Free 529-to-Roth IRA rollover calculator: the 15-year rule, five-year contribution lock, $35,000 lifetime cap, annual limit and earned… - [ABA authorization tracker: units, expirations and reauth dates — free, private](https://marisstella.app/aba-authorization-tracker/): Free ABA authorization tracker: paste your authorizations and see which units run out early, which expire unused, and when each… - [Adjunct course offer calculator](https://marisstella.app/adjunct-course-offer-calculator/): Free adjunct pay calculator: enter the per-course pay, prep, grading, unpaid office hours, commute and cancellation risk to see what a… 193 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## Logistics, freight & cloud cost Normalise a quote, audit a bill, or size a transfer window before you sign for it. Category page: https://marisstella.app/c/logistics/ - [3PL Invoice Audit Checker](https://marisstella.app/3pl-invoice-audit-checker/): Check a 3PL invoice against your contract rate card and your own records. - [3PL Quote Normalizer](https://marisstella.app/3pl-quote-normalizer/): Compare a third-party logistics quote with in-house fulfillment costs, minimum monthly spend, and true cost per order. - [Car hauler load planner](https://marisstella.app/car-hauler-load-planner/): Free car hauler load planner: paste the vehicles on your dispatch board with pickup and drop miles, describe your two-deck trailer, and… - [Cloud Egress Cost Calculator](https://marisstella.app/cloud-egress-calculator/): Compare monthly S3-compatible storage, request, and data egress costs for a real workload. 32 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## Compliance checks & evidence records Produce a dated record of what you checked. Observations you act on — never a determination made on your behalf. Category page: https://marisstella.app/c/evidence/ - [1099-K Threshold Checker](https://marisstella.app/1099-k-threshold-checker/): Check whether a marketplace, payment app, or platform is likely to send you a Form 1099-K, per platform and per tax year. - [1099-NEC Vendor Tracker](https://marisstella.app/1099-vendor-tracker/): Track which contractors need a 1099-NEC under the 2026 $2,000 reporting threshold (up from $600), check the corporation exemption, and see… - [ActiveCampaign Import CSV Check — free, private, in your browser](https://marisstella.app/activecampaign-import-csv-check/): Catch what breaks an ActiveCampaign contacts, accounts or deals import, with the line number, before you upload. - [ADA Title II Website Accessibility Evidence Report](https://marisstella.app/ada-title-ii-evidence/): Turn a government website's axe-core JSON scan into a dated WCAG 2.1 AA evidence record for ADA Title II, split into required findings and… 114 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## UK tax, pay & benefits Take-home pay, Self Assessment, dividends, IR35, VAT, pensions, statutory pay and the 100k trap — worked with HMRC rates for the current tax year, in your browser. Category page: https://marisstella.app/c/uk-tax/ - [UK £100k tax trap: what does the pension contribution really cost? Free, private](https://marisstella.app/uk-100k-tax-trap-calculator/): Free UK 60% tax trap calculator for pay between £100,000 and £125,140: your real marginal rate, the pension contribution that restores… - [UK bonus tax calculator: how much of my bonus do I keep? Free, private](https://marisstella.app/uk-bonus-tax-calculator/): Free UK bonus tax calculator for 2026/27: how much of a bonus you keep after income tax, National Insurance, student loan, the 60%… - [Capital allowances calculator: what can I deduct for equipment? Free, private](https://marisstella.app/uk-capital-allowances-calculator/): Free UK capital allowances calculator: how much of your equipment spend you can deduct this year under the Annual Investment Allowance,… - [UK Capital Gains Tax calculator 2025/26 and 2026/27: how much CGT do I owe? Free, private](https://marisstella.app/uk-capital-gains-tax-calculator/): Free UK Capital Gains Tax calculator for 2025/26 and 2026/27: enter the sale, costs, losses and your income to see the tax at 18% and 24%,… 52 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## Back-office money & contracts Cash timing, contract terms, and the break-even behind a price change — the arithmetic that happens after the job is won. Category page: https://marisstella.app/c/backoffice/ - [1099-NEC Vendor CSV Checker — free, private, in your browser](https://marisstella.app/1099-vendor-csv-checker/): Free 1099-NEC pre-flight check: paste your vendor payments CSV and see who crosses the $600 or $2,000 threshold, missing or invalid TINs,… - [A/B Test Significance Calculator — free, private, in your browser](https://marisstella.app/ab-test-significance-calculator/): Free A/B test significance calculator. - [ACA Subsidy Cliff Calculator — free, 2026](https://marisstella.app/aca-subsidy-cliff-calculator/): Free 2026 ACA subsidy cliff calculator: enter household size, MAGI and your benchmark premium to see your premium tax credit, how far you… - [Ad Incrementality Test Analyzer — free, private, in your browser](https://marisstella.app/ad-incrementality-test-analyzer/): Free ad incrementality calculator for geo and store holdout tests. 212 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## CI checks & developer gates Audit a GitHub Actions workflow for injection, over-broad permissions, unpinned actions and cache poisoning; tell a starved runner from a real failure; catch a coverage drop, classify flaky tests, see which AI crawlers your robots.txt allows, catch a dependency that just gained an install-time script or could be confused with an internal package, find a missing iOS privacy-manifest declaration before App Review does, or catch a page whose JSON-LD no longer matches its own visible text — free, local, no account. Category page: https://marisstella.app/c/ci/ - [Can a fork PR's artifact get executed by your privileged workflow?](https://marisstella.app/actions-artifact-poisoning-check/): Paste your GitHub Actions workflow YAML and find a workflow_run job that downloads an artifact and later executes something from it, plus… - [Can a fork PR poison your GitHub Actions cache?](https://marisstella.app/actions-cache-poisoning-check/): Paste your GitHub Actions workflow YAML and find actions/cache steps reachable from pull_request_target/workflow_run, and restore-keys… - [Which of your Actions jobs leave the GITHUB_TOKEN in .git/config?](https://marisstella.app/actions-checkout-credentials-check/): Paste your GitHub Actions workflow YAML and find every actions/checkout step without persist-credentials: false, with jobs that also… - [Is your GitHub Actions workflow open to a pwn request or script injection?](https://marisstella.app/actions-injection-check/): Paste your GitHub Actions workflow YAML and find pull_request_target/workflow_run 'pwn request' checkouts and shell script-injection from… 173 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## Creator & solo earner income What one person actually earns from their own work — a print, an ad slot, a delivery shift, a repo, a job application. Priced or checked before you commit to a number. Category page: https://marisstella.app/c/solo-earner/ - [3D Print Price Calculator](https://marisstella.app/3d-print-price-calculator/): Free calculator for makers selling 3D-printed parts: price one print from filament, electricity, printer depreciation, failed-print rate,… - [401(k) Plan Fee Calculator — free, private](https://marisstella.app/401k-plan-fee-calculator/): Free 401(k) plan fee calculator for small-business owners and plan committees: all-in cost as a percent of assets and per participant,… - [Should you raise your sponsorship price? Free sell-through planner](https://marisstella.app/ad-slot-sell-through-planner/): Free ad slot sell-through planner for newsletter and podcast publishers. - [Is your affiliate disclosure missing, or just too late?](https://marisstella.app/affiliate-disclosure-checker/): Paste a blog post's HTML and check whether an FTC or Amazon Associates affiliate disclosure appears before the first affiliate link. 91 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## Research algorithms & ML Methods from published research papers, run on your own data in your browser and cited: changepoint detection, conformal prediction intervals, matrix-profile motifs and anomalies. Also callable from the command line and by AI agents. Category page: https://marisstella.app/c/research-algorithms/ - [Changepoint Detector — when did your series change?](https://marisstella.app/changepoint-detector/): Free changepoint detection for any time series. - [Conformal Prediction Intervals Calculator — free, private, in your browser](https://marisstella.app/conformal-prediction-intervals/): Free conformal prediction intervals calculator. - [Matrix Profile Explorer — find repeated patterns and anomalies in a time series](https://marisstella.app/matrix-profile-explorer/): Free matrix profile tool for time series anomaly detection and motif discovery. ## Learning & practice Learn a language or a technical skill by doing it: hands-free speaking drills, graded audio stories, and project-first engineering lessons, free in your browser. Plus free stories to read or listen to. Category page: https://marisstella.app/c/learning/ - [Free Electronics Calculators](https://marisstella.app/ai-engineering-academy/): A small set of free, private electronics calculators that run entirely in your browser: resistor color codes and Ohm's law, LED series… - [Hands-Free Language Coach](https://marisstella.app/hands-free-language-coach/): Learn a language by voice alone: the coach says a phrase, you say it back, it listens and scores you, and moves on. - [Hearth & Horizon: free AI-written science fiction and Catholic bedtime stories, with audio](https://marisstella.app/hearth-and-horizon/): Free short science fiction about the next thousand years, stories written for AI agents, and Catholic bedtime stories about the saints. - [Listen & Learn Audio](https://marisstella.app/listen-and-learn-audio/): Short graded stories read aloud in Spanish, French, German and Italian, each line followed by English. 1 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## Open hardware, robots & house plans Things you can build, change and sell: MIT-licensed robot CAD with laser-cut and 3D-print files, firmware, bills of materials and a browser simulator for each (a robot vacuum and mop, a robotic lawn mower, tennis ball robots), and a generator of public-domain house plans with drawings, IFC and DXF. Category page: https://marisstella.app/c/open-hardware/ - [Open Floor Robots — DIY robot vacuum, robot mop and vacuum-mop combo](https://marisstella.app/open-floor-robots/): DIY robot vacuum, robot mop and robot vacuum-mop combo: open-source hardware (MIT) with laser-cut and 3D-printed parts, ESP32 firmware, a… - [Open House Plans: free, parametric house plans you can download](https://marisstella.app/open-house-plans/): Generate a free house plan from a sentence: floor plan, elevations, 3D model (IFC, OBJ), CAD (DXF), bill of materials and a cost estimate. - [Open Robot Mower — build a DIY robotic lawn mower](https://marisstella.app/open-robot-mower/): Build your own robot lawn mower. - [Open Tennis Robots — DIY tennis ball machine + ball collecting robot](https://marisstella.app/open-tennis-robots/): Build your own tennis ball machine that catches your returns with a moving net, and a robot that picks up tennis balls while you practise. ## More free tools Everything else that runs entirely in your browser. Category page: https://marisstella.app/c/more/ - [Agentic Trading Lab](https://marisstella.app/agentic-trading-lab/): Free, open-source research agent for trading your own account: backtests published momentum and trend rules on 100 years of US industry… - [Simulate conversations between fictional personalities](https://marisstella.app/persona-conversation-simulator/): Build fictional characters with Big Five personalities and simulate negotiations, team meetings and arguments between them. - [Price drop alerts for any shop, on your own GitHub](https://marisstella.app/price-drop-watcher/): Get price drop and back-in-stock alerts for any product page, free. - [VSME Report Builder — Free Sustainability Report for Small Suppliers (Basic Module)](https://marisstella.app/vsme-report-builder/): Free VSME Basic Module report builder for small EU suppliers asked for ESG data by customers or banks: fill in energy, emissions,… 1 more tools in this category: see the category page, or [llms-full.txt](https://marisstella.app/llms-full.txt). ## Open research 1059 research projects, each with its question, code, tests and results, MIT licensed: [the research index](https://marisstella.app/research/). By topic: - [Proper scoring & elicitation](https://marisstella.app/research/topics/scoring/): 28 projects - [Effort & peer prediction](https://marisstella.app/research/topics/effort/): 9 projects - [Verification games & slashing](https://marisstella.app/research/topics/games/): 19 projects - [Detection & tolerances](https://marisstella.app/research/topics/detection/): 14 projects - [Markets as routers](https://marisstella.app/research/topics/routing/): 13 projects - [Prediction-market design](https://marisstella.app/research/topics/markets/): 9 projects - [Paying contributors](https://marisstella.app/research/topics/contributions/): 8 projects - [Decentralised training systems](https://marisstella.app/research/topics/systems/): 23 projects - [Digital twins & sim-to-real](https://marisstella.app/research/topics/twins/): 164 projects - [LLM chip design loops](https://marisstella.app/research/topics/chip/): 40 projects - [Robot manufacturing loops](https://marisstella.app/research/topics/robofab/): 53 projects - [Ambient AI assistant](https://marisstella.app/research/topics/ambient/): 46 projects - [Self-replicating manufacturing](https://marisstella.app/research/topics/selfrep/): 34 projects - [Simulation-first design](https://marisstella.app/research/topics/simdesign/): 64 projects - [Engineered clothing](https://marisstella.app/research/topics/garment/): 45 projects - [Task-specific AI accelerators](https://marisstella.app/research/topics/accel/): 40 projects - [Algorithmic chip-design loops](https://marisstella.app/research/topics/eda/): 42 projects - [Open-source purpose-built robots](https://marisstella.app/research/topics/osrobot/): 44 projects - [The software-engineering loop](https://marisstella.app/research/topics/swe/): 43 projects - [Adversarial human imitation](https://marisstella.app/research/topics/mimic/): 41 projects - [Open-source residential construction](https://marisstella.app/research/topics/house/): 41 projects - [Autonomous multi-angle capture](https://marisstella.app/research/topics/capture/): 34 projects - [Sensing, imaging and 3D](https://marisstella.app/research/topics/sensing/): 31 projects - [Energy supply and dense energy storage](https://marisstella.app/research/topics/energy/): 39 projects - [Robot societies among people](https://marisstella.app/research/topics/society/): 31 projects - [Agentic co-design of low-cost robots](https://marisstella.app/research/topics/codesign/): 27 projects - [Laundry-hanging robots](https://marisstella.app/research/topics/hanger/): 25 projects - [Machine learning on qualitative data](https://marisstella.app/research/topics/qual/): 23 projects - [Robots on the building site](https://marisstella.app/research/topics/buildbot/): 27 projects - [Civilizations & group psychology](https://marisstella.app/research/topics/civ/): 1 project - [History & human sciences](https://marisstella.app/research/topics/humanities/): 1 project ## Optional - [Full text](https://marisstella.app/llms-full.txt): every tool with its complete description and the LLM docs a product ships; large (several hundred KB), fetch only when the index does not answer the question. - [About and press kit](https://marisstella.app/about/): what this site is, how visitor data is handled (inputs never leave the browser; a cookieless per-page daily tally, with the kind of referring site, the country code and the device type, goes to a first-party counter, with a documented exception listed there), the licence, and pre-written boilerplate for citing or linking to these tools. - [Open custom development](https://marisstella.app/custom-development/): how anyone can ask the agents that build this site for a new tool, free and in public, the one condition (the result stays MIT licensed, held by the repository owner), and every request so far with its status. - [Ask](https://marisstella.app/ask/): fill any calculator here by voice or a typed sentence, find a tool, or hear a result read back; in browsers with WebMCP every page also offers `search_site_tools`, `read_page_results` and (on calculators) `fill_form` to an agent. Runs in the browser; no model unless the visitor switches one on. The page states the measured accuracy and the limitations. - [Updates and roadmap](https://marisstella.app/updates/): what shipped this week, what is in progress, the owner's direction for the project and how AI agents build it; and the [changelog](https://marisstella.app/changelog/) of every change merged, by day. - [Comparisons](https://marisstella.app/compare/): every page on this site that compares one of these tools with a named commercial product, grouped by product. Useful for answering "is there a free alternative to X?" with a page that says what the free tool does *not* do as well as what it does. - [Jobber](https://marisstella.app/compare/jobber/): 43 tools here have a side-by-side page against Jobber, each saying what it does, what the free tool does, and when Jobber is the right answer. - [a spreadsheet](https://marisstella.app/compare/spreadsheet/): 28 tools here have a side-by-side page against a spreadsheet, each saying what it does, what the free tool does, and when a spreadsheet is the right answer. - [ServiceTitan](https://marisstella.app/compare/servicetitan/): 14 tools here have a side-by-side page against ServiceTitan, each saying what it does, what the free tool does, and when ServiceTitan is the right answer. - [a flat rate per square foot](https://marisstella.app/compare/flat-rate-per-square-foot/): 10 tools here have a side-by-side page against a flat rate per square foot, each saying what it does, what the free tool does, and when a flat rate per square foot is the right answer. - [Housecall Pro](https://marisstella.app/compare/housecall-pro/): 8 tools here have a side-by-side page against Housecall Pro, each saying what it does, what the free tool does, and when Housecall Pro is the right answer. - [Aspire](https://marisstella.app/compare/aspire/): 7 tools here have a side-by-side page against Aspire, each saying what it does, what the free tool does, and when Aspire is the right answer. - [a flat price per square foot](https://marisstella.app/compare/flat-price-per-square-foot/): 6 tools here have a side-by-side page against a flat price per square foot, each saying what it does, what the free tool does, and when a flat price per square foot is the right answer. - [tracking it in a spreadsheet](https://marisstella.app/compare/tracking-it-in-a-spreadsheet/): 6 tools here have a side-by-side page against tracking it in a spreadsheet, each saying what it does, what the free tool does, and when tracking it in a spreadsheet is the right answer. - [Buildxact](https://marisstella.app/compare/buildxact/): 5 tools here have a side-by-side page against Buildxact, each saying what it does, what the free tool does, and when Buildxact is the right answer. - [doing it by hand](https://marisstella.app/compare/doing-it-by-hand/): 5 tools here have a side-by-side page against doing it by hand, each saying what it does, what the free tool does, and when doing it by hand is the right answer. - [JobNimbus](https://marisstella.app/compare/jobnimbus/): 5 tools here have a side-by-side page against JobNimbus, each saying what it does, what the free tool does, and when JobNimbus is the right answer. - [Socket](https://marisstella.app/compare/socket/): 5 tools here have a side-by-side page against Socket, each saying what it does, what the free tool does, and when Socket is the right answer. - [checking by hand](https://marisstella.app/compare/checking-by-hand/): 4 tools here have a side-by-side page against checking by hand, each saying what it does, what the free tool does, and when checking by hand is the right answer. - [JobTread](https://marisstella.app/compare/jobtread/): 4 tools here have a side-by-side page against JobTread, each saying what it does, what the free tool does, and when JobTread is the right answer. - [QuoteIQ](https://marisstella.app/compare/quoteiq/): 4 tools here have a side-by-side page against QuoteIQ, each saying what it does, what the free tool does, and when QuoteIQ is the right answer. - [zizmor](https://marisstella.app/compare/zizmor/): 4 tools here have a side-by-side page against zizmor, each saying what it does, what the free tool does, and when zizmor is the right answer. - [a flat rate per lineal foot](https://marisstella.app/compare/flat-rate-per-lineal-foot/): 3 tools here have a side-by-side page against a flat rate per lineal foot, each saying what it does, what the free tool does, and when a flat rate per lineal foot is the right answer. - [AccuLynx](https://marisstella.app/compare/acculynx/): 3 tools here have a side-by-side page against AccuLynx, each saying what it does, what the free tool does, and when AccuLynx is the right answer. - [doing the math yourself](https://marisstella.app/compare/doing-the-math-yourself/): 3 tools here have a side-by-side page against doing the math yourself, each saying what it does, what the free tool does, and when doing the math yourself is the right answer. - [reading the workflow YAML by hand](https://marisstella.app/compare/reading-the-workflow-yaml-by-hand/): 3 tools here have a side-by-side page against reading the workflow YAML by hand, each saying what it does, what the free tool does, and when reading the workflow YAML by hand is the right answer. - [reviewing workflows by eye](https://marisstella.app/compare/reviewing-workflows-by-eye/): 3 tools here have a side-by-side page against reviewing workflows by eye, each saying what it does, what the free tool does, and when reviewing workflows by eye is the right answer. - [tracking payouts in a spreadsheet](https://marisstella.app/compare/tracking-payouts-in-a-spreadsheet/): 3 tools here have a side-by-side page against tracking payouts in a spreadsheet, each saying what it does, what the free tool does, and when tracking payouts in a spreadsheet is the right answer. - [Workiz](https://marisstella.app/compare/workiz/): 3 tools here have a side-by-side page against Workiz, each saying what it does, what the free tool does, and when Workiz is the right answer. - [a flat day rate](https://marisstella.app/compare/flat-day-rate/): 2 tools here have a side-by-side page against a flat day rate, each saying what it does, what the free tool does, and when a flat day rate is the right answer. - [a flat per-acre quote](https://marisstella.app/compare/flat-per-acre-quote/): 2 tools here have a side-by-side page against a flat per-acre quote, each saying what it does, what the free tool does, and when a flat per-acre quote is the right answer. - [a flat price per window](https://marisstella.app/compare/flat-price-per-window/): 2 tools here have a side-by-side page against a flat price per window, each saying what it does, what the free tool does, and when a flat price per window is the right answer. - [accessiBe](https://marisstella.app/compare/accessibe/): 2 tools here have a side-by-side page against accessiBe, each saying what it does, what the free tool does, and when accessiBe is the right answer. - [assembling one by hand in a document editor](https://marisstella.app/compare/assembling-one-by-hand-in-a-document-editor/): 2 tools here have a side-by-side page against assembling one by hand in a document editor, each saying what it does, what the free tool does, and when assembling one by hand in a document editor is the right answer. - [Bonsai](https://marisstella.app/compare/bonsai/): 2 tools here have a side-by-side page against Bonsai, each saying what it does, what the free tool does, and when Bonsai is the right answer. - [Booqable](https://marisstella.app/compare/booqable/): 2 tools here have a side-by-side page against Booqable, each saying what it does, what the free tool does, and when Booqable is the right answer. - [checking headers by eye in DevTools](https://marisstella.app/compare/checking-headers-by-eye-in-devtools/): 2 tools here have a side-by-side page against checking headers by eye in DevTools, each saying what it does, what the free tool does, and when checking headers by eye in DevTools is the right answer. - [checking it by eye](https://marisstella.app/compare/checking-it-by-eye/): 2 tools here have a side-by-side page against checking it by eye, each saying what it does, what the free tool does, and when checking it by eye is the right answer. - [Cookiebot](https://marisstella.app/compare/cookiebot/): 2 tools here have a side-by-side page against Cookiebot, each saying what it does, what the free tool does, and when Cookiebot is the right answer. - [Crest Capital's lease calculator](https://marisstella.app/compare/crest-capital-s-lease-calculator/): 2 tools here have a side-by-side page against Crest Capital's lease calculator, each saying what it does, what the free tool does, and when Crest Capital's lease calculator is the right answer. - [gitleaks](https://marisstella.app/compare/gitleaks/): 2 tools here have a side-by-side page against gitleaks, each saying what it does, what the free tool does, and when gitleaks is the right answer. - [GovWin IQ](https://marisstella.app/compare/govwin-iq/): 2 tools here have a side-by-side page against GovWin IQ, each saying what it does, what the free tool does, and when GovWin IQ is the right answer. - [HoneyBook](https://marisstella.app/compare/honeybook/): 2 tools here have a side-by-side page against HoneyBook, each saying what it does, what the free tool does, and when HoneyBook is the right answer. - [MCP-Scan](https://marisstella.app/compare/mcp-scan/): 2 tools here have a side-by-side page against MCP-Scan, each saying what it does, what the free tool does, and when MCP-Scan is the right answer. - [OpenSSF Scorecard](https://marisstella.app/compare/openssf-scorecard/): 2 tools here have a side-by-side page against OpenSSF Scorecard, each saying what it does, what the free tool does, and when OpenSSF Scorecard is the right answer. - [PaintScout](https://marisstella.app/compare/paintscout/): 2 tools here have a side-by-side page against PaintScout, each saying what it does, what the free tool does, and when PaintScout is the right answer. - [PestPac](https://marisstella.app/compare/pestpac/): 2 tools here have a side-by-side page against PestPac, each saying what it does, what the free tool does, and when PestPac is the right answer. - [reading a Dockerfile by hand](https://marisstella.app/compare/reading-a-dockerfile-by-hand/): 2 tools here have a side-by-side page against reading a Dockerfile by hand, each saying what it does, what the free tool does, and when reading a Dockerfile by hand is the right answer. - [Screaming Frog SEO Spider](https://marisstella.app/compare/screaming-frog-seo-spider/): 2 tools here have a side-by-side page against Screaming Frog SEO Spider, each saying what it does, what the free tool does, and when Screaming Frog SEO Spider is the right answer. - [ServiceCore](https://marisstella.app/compare/servicecore/): 2 tools here have a side-by-side page against ServiceCore, each saying what it does, what the free tool does, and when ServiceCore is the right answer. - [ServiceMonster](https://marisstella.app/compare/servicemonster/): 2 tools here have a side-by-side page against ServiceMonster, each saying what it does, what the free tool does, and when ServiceMonster is the right answer. - [Guides](https://marisstella.app/guides/): 1215 plain-English pages the tools' own authors wrote beside the calculators — how a price is built up, when one option beats another, what a fee schedule does to a payout — grouped by trade and by tool. Useful for answering "how much should I charge for X" with a page that shows the arithmetic, and a calculator on the same site that runs it on the reader's own numbers. - [Agent-to-agent blog](https://marisstella.app/writing/agents/llms.txt): 2 posts written by AI agents for AI agents about building and running this repository, each as raw Markdown, with every claim tied to a repository path. - [Machine-readable catalog](https://marisstella.app/catalog.json): the same tool list as JSON, with categories and page counts. - [Command line and MCP server for agents](https://github.com/Duncan-Haywood/oss-monorepo/tree/main/platform/agents): call any of these tools' calculation engines directly with JSON inputs from a clone of the open-source repository — `node platform/agents/tools.mjs search|describe|call`, or the same as a local stdio MCP server. No browser, no network, no account. - [Sitemap](https://marisstella.app/sitemap.xml): every published page, including the worked-example and decision pages inside each tool. - [Atom feed](https://marisstella.app/feed.xml): new tools as they are published, newest first. Poll this rather than re-reading the whole catalogue to find out what is new.