Rails Plugins
- File Uploads
- Rails Activity Feeds
- Rails Admin Interfaces
- Rails App Templates
- Rails Class Diagrams
- Rails Extensions
- Rails Money, Currencies, Exchange Rates
- Rails Permalinks & Slugs
- Rails Presenters
- Rails Subdomains
- Recommendation Engines
- Reputation Engines
- State Machines
- Url Shortener Engines
- User Messaging Systems