RubyLaser is an open source alternative to ruby-toolbox.
RubyLaser lets you browse and search gems (fulltext and tegs) and displays aggregated data from rubygems and github.
Tags and search by tags are supported, work on categories has started but is not finished.
The project was started by the first cohort at WebDev Camp and has good basic functionality (especially now that ruby-toolbox is down)
But more than that, it is open source, and so all those features you ever wished for are yours for the making !
WebDev Camp is committed to maintaining the site , server and project.
So now it's up to you (us!) to make something awesome from something good (see https://rubylaser.org/contribute)
Site: https://rubylaser.org/
Project: https://github.com/webdev-camp/laser
Torsten