Rizzoma - Email and IM are linear contextless communication tools.
Smartwaiver - Smartwaiver is an online waiver solution for business to manage signed waivers and customer data.
Walkaround - Walkaround is a variant of Wave, based on the Apache Wave code base, that runs on App Engine.
WaiverForever - Electronic waiver system for small businesses
Collaba - Collaba is an easy-to-install, double-click-to-run, server software that provides integrated services such as: e-mail, calendaring, files & documents, assignments, blogs, multimedia chat, forums, bookmarks, web publishing, wiki, single sign-on, LDAP…
WaiverSign - Cloud-based waiver and release of liability signing software