Everything in the catalog

Parses code with many language parsers and displays the syntax tree for exploring transforms.

Generates deterministic SVG avatars from a name and palette.

Searchable library of brand SVG logos with copy and download.

Open-source invoice generator with thirteen templates, custom colours and logo, exporting PDF.

Playable explainer on how cooperation and distrust spread, built around the repeated prisoner's dilemma.

Generates CSS for soft-UI neumorphic shadows on a configurable shape.

Web interface for SVGO with toggles for each optimization and a live before/after preview.

Builds editable fantasy world maps with states, religions, cultures, burgs and routes; exports to image or data files.

Run TIC-80 fantasy computer carts in the browser, a tiny retro console for homebrew games.

Builds scripts that harden privacy and security settings on Windows, macOS and Linux, chosen by checkbox.

Draw boxes, arrows and lines on a text grid to make diagrams you can paste into code comments or READMEs.

Draws a JavaScript regular expression as a railroad-style diagram to help you read it.

Compares Amazon EC2 instance types by specs and price across regions.

3D walk-through of the computations inside a small GPT-style language model.

JupyterLab running entirely in the browser with a WebAssembly Python kernel, no server needed.

Create a meeting poll with candidate dates and share the link; no login needed for voters.

Edit SVG path data as text or by dragging points, with relative and absolute commands.

Browser MQTT 5.0 client that connects over WebSocket to publish and subscribe to topics.

Open-source web app that writes privacy policies and terms of use for mobile and web apps.

Write dated events in plain text and view them as a timeline, calendar or Gantt chart.

Typing practice that adapts lessons to your weakest keys as you type.

Block-based programming editor for making games, stories and animations, usable without logging in.

Shows what the compiler generates behind C++ features by expanding your code into explicit source.

Drag-and-drop section templates and a Markdown editor for assembling a project README.