Userswitch is a Rails plugin for switching between commonly used roles and users. It's particularly useful for development and staging environments when you often need to switch between various accounts. It saves you from the hassle of logging in or out.

Not a markup language - rather, an library for processing user-contributed text that handles the common ways in which ordinary users add meaning, structure and formatting using plain text.

A jQuery plugin provides to display time in user's timezone.

This gem lets you add a 'has_timezone' to a User, Contact or Account that has a city, state, country or zip and it will add the #timezone attribute that will automatically populate the timezone attribute.

Provide time zone support for User models in Rails applications

A much faster version of the usesguid plugin for Rails ported to a gem (uses database for GUID generation)

Prefer urandom to OpenSSL

A lightweight, dependency-free Ruby gem for accessing USGS NWIS API data (sites, instantaneous values, daily values)

An ultra portable url shortener

The ruby classes that takls to ushahidi platforms. ref: http://wiki.ushahidi.com/doku.php?id=ushahidi_api

A gem for validating Australian Government Unique Student Identifiers (USI)

Usine (french word for factory) is a wrapper around factory_girl for Trailblazer’s operations.

Usmu is a static site generator built in Ruby that leverages the Tilt API to support many different template engines. It supports local generation but is designed to be used with the web-based editor.

Github Pages publishing plugin for Usmu.

S3 publishing plugin for Usmu.

XML sitemap generator plugin for Usmu.

The base USNO gem provides a namespace for other USNO::* gems.

Obtain the circumstances of recent and upcoming solar or lunar eclipses for any location.

Obtain the circumstances of recent and upcoming lunar eclipses for any location

Obtain the circumstances of recent and upcoming solar eclipses for any location