Bookify is a gem for converting Markdown documents into book style, two-column PDFs. It starts by converting the Markdown to HTML using Redcarpet. Then it walks through the DOM, and when it encounters a registered component type, renders it using Prawn PDF.
Jargon (no longer active) is a publishing platform for writing about code. It supports an extended Markdown syntax for embedding code snippets in articles, and publishing is handled by checking in content to a GitHub repository.
ChessForge is a chess opening explorer written in Ember on top of a Rails API. It has a database of 75 million chess positions and shows frequency and win / loss / draw percentages for different opening moves, bucketed by player strength.
To play around with Rails 5's new Action Cable feature, I built a simple chess server that allows two people to play a game a chess.
A Markov chain Twitter bot that uses Dwarf Fortress stories as its corpus.
whatfoodsareinseason.com is a Sinatra app that shows what fruits and vegetables are in season in your state.
Withings-graphs is a small app that connects to the Withings OAuth API and displays data using amCharts.
Evolution is a program I wrote that tries to mimic a source image by randomly drawing polygons.
The Urbanairship Ruby gem is a library I wrote while developing Groupon's push notification system. It allows you to send push notifications to iOS and Android phones using the Urban Airship API.
I maintained the gem for two years while working at Groupon, and it's now maintained by the Urbanairship team.
Grams was a weekend hack project I did that collects Instagrams from a specific neighborhood and tweets the best ones.
Lovemap is a tile-based mapping engine for the LÖVE game development framework written in Lua.
text/cats is an innovative content format that represents JSON data in the shape of playful kittens. It was first used in Groupon's public and internal APIs.