- query_trace 172 Adds query origin tracing to your logs.
- relix 24 A Redis-backed indexing layer that can be used with any (or no) backend data storage.
- drbfire 8 DRbFire provides a protocol for DRb that enables bi-directional communication (such as server-side callbacks) through firewalls without requiring any ports to be opened.
- 23hacks 7 Source of Nathaniel Talbott's RailsConf 2008 talk
- active_model 7 Provides Rails model services (such as validations) to non-ActiveRecord descendants.