enforcer: DSL for managing lots of github collaborators
gemcutter: Awesome gem hosting
jekyll: Static site generation made easy
report_card: Build metrics from your CI server

beardo: Ruby api for Co-op
snake: A simple snake game, written in Shoes
vim-fu: Using git submodules to pull down the latest and greatest vim plugins

acts_like_git: ActiveRecord backed up by git to allow versioning
clearance: Rails authentication engine for developers that test
factory_girl: Churn out ActiveRecord models like a boss
integrity: CI that doesnt suck
metric_fu: A fistfull of code metrics
paperclip: Simple file attachments for Rails
shoulda: Elegant, understandable testing framework

Please check out my resume for this stuff.