Biogems.info is a new site for keeping track of new and existing Bioruby plugins. Plugins are separate code libraries that split functionality out of the Bioruby main tree. The idea is to have a core Bioruby release and to allow Ruby developers to contribute to Bioruby through plugins. According to Bonnal, the maintainer of biogem (the bio-plugin crafting tool), plugins are separately maintained and may represent experimental or work in progress.
To read more about Bioruby plugin system please refer to the wiki page on plugins.