MojoMojo is the most complex open source Catalyst application developed to date.
It is a Web2.0 wiki with AJAX live preview, hierarchical structure, tags, diffs, pluggable syntax, permissions/ACL, attachments, RSS feeds, a photo gallery, edit conflict resolution via 3-way merge, themes/skinning, localization, built-in full-text search, and a reverse index. Since it's built on top of the Perl Catalyst Web framework, MojoMojo supports any Web server, and includes its own standalone one. It also support any database backend supported by the DBIx::Class ORM, and has been successfully tested with PostgreSQL, SQLite, and MySQL.
Clipping is a handy way to collect important slides you want to go back to later.