FOLD file format for origami models, crease patterns, etc.
Fast math typesetting for the web.
Tool for drawing diagrams on a grid, combining grids of SVGs into a big SVG figure
Customize replacements in markdown-it typographer
Create custom SMTP servers on Node.JS version 4
Send e-mail with Node.JS version 4
Custom level design for Recursed via spreadsheets
Synchronize form state (and other state) with URL
Tweaked spell checker for CodeMirror
Convert LaTeX to SVG via Web Worker
Custom markdownlint rule for checking internal links like those generated by Github
Attendance measurement for Comingle meetings