FastExists drastically reduces database lookups in Ruby on Rails applications by utilizing thread-safe probabilistic filters (Bloom Filters, Cuckoo Filters, HyperLogLog) while preserving the database as the single source of truth.

FastExt is a framework for creating enterprise-level application style interfaces. FastExt is released as a Ruby Gem. The gem is to be installed within a Ruby on Rails 3 application.

Sets all sqlite connections to be as performant as possible while sacrificing of data integrity.

fast_tree is an implementation of tree structure using nested sets model

Fast versioning extension for paper_trail

Using Action Mailer, gem sends all tasks from Fat Free CRM to your Wunderlist account.

Models define access rules via a DSL. Controllers call auth_required. Access denied returns 404.

Schedule emails to be sent at a later date from your Rails app.

Favorite stuff with this gem.

A dropin utility that adds favourites functionality to any object

Overrides the original pagination with the paginative gem

Faye Online user list and time count

fbcat - command-line tools for built-in football catalog (reference) dbs incl. leagues, clubs, & more

Support for sessions tied to Facebook users.

fbtxt2sqlite - read football.txt match schedules & more into sqlite database

A user class that is created with Facebook

Description of Fcid.

A Rails engine for administrative access to a Fedora Commons repository based on the Hydra Project repository application framework.

Fdbq::Rails. A Rails integration for Fdbq JS plugin.

A gem to help manage toggling features on and off in Rails applications without having to re-deploy. Includes a preconfigured page for gate management and an executable for feature gate code cleanup in your codebase after a feature has been deployed.