XWiki is a WikiWiki clone written in Java that supports many popular features of other Wikis like the Wiki syntax, version control, attachments, security, and searching, but also many advanced features like templates, database and dynamic development using scripting languages (Velocity, Groovy, Ruby, Python, PHP, and more), an extension system and skinability, J2EE scalability, an XML/RPC remote API, statistics, RSS feeds, PDF exporting, WYSIWYG editing, an Office viewer and importer, and a lot more.
Gollem is a Web-based file manager that provides the ability to fully manage a hierarchical file system stored in a variety of backends such as a SQL database, as part of a real filesystem, or on FTP, Samba or SSH servers. It supports uploading and downloading of files, basic file operations, permissions support, and MIME recognition and viewing of files through the Horde MIME library. It is fully internationalized and translatable.
Interleave is a Web-enabled business process automation application. It enables you to model your business process like purchasing, project management, and contract management and make it available online. It's meant to replace processes which currently rely on paper, email, or spreadsheets and it has a very good workflow engine. You can create invoices, export to RTF and PDF based on templates, export to MS Excel, interpret incoming email, and publish your data to the Web.