Formative is an extraction of the custom form builder I used in my last couple of Rails projects. It is the simplest thing that could possibly work for me. YMMV.

Group your checkboxes like grouped select via “grouped_collection_select” in Rails. This gem adds a new Formtastic input type “grouped_check_boxes”, that helps you group long lists of checkboxes.

Have 3-state radiobuttons instead of a 2-state checkbox for your Boolean columns which can store NULL. This gem: 1. Provides a custom Formtastic input type `:tristate_radio` which renders 3 radios (“Yes”, “No”, “Unset”) instead of a checkbox (only where you put it). 2. Teaches Rails recognize `"n...

Like fromtastic only works with DataMapper and Sinatra or whatever.

A Ruby library for the Forrst API.

Provides an easy way to interact with the 42 API in any kind of application.

This is a library to extend Forwardable functions

FoundationKit provides....

Fourchan Kit is a Ruby wrapper and tool for the 4chan API. Use Fourchan Kit to interact with the API using Ruby, or use the tool to interact with the threads on 4chan.

Simple foursquare api client

FourthBase provides support for Rails to manage dual databases by extending ActiveRecord tasks that create, migrate, and test your databases.

A collection of Stern-Brocot based models and methods

This is a collection of useful tools to help you in more easily instrumenting Ruby applications for the Prometheus monitoring system.

Client library for accessing Fraudpointer REST API

Build faust-executable DSP graphs in Ruby DSL with ruby2faust; or convert Faust to Ruby with faust2ruby.

A JSON API in Sinatra for scouting FRC competitions, and that manages the database using Mongoid.

Ruby client for the FreeAgent API.

FreeLing::Analyzer is a Ruby wrapper around `analyzer`, a binary tool included in FreeLing's package that allows the user to process a stream of text with FreeLing.

A Ruby script to analyze VLAN distribution on network devices, generating tables or PNG images.

Freight carrier API and website abstraction library for transportation management systems (TMS)