Druid is an open source unified communications platform, built around Asterisk, IMAP & Jabber/XMPP. Druid gives an organization access to a IP communications platform that bringing together voicemail, VOIP, mobile phone, faxes and instant messaging.

Key features:

1. Unified mailbox for faxes and voicemail
2. IM-based call control and messaging
3. Plug & Play IP handset provisioning for Cisco, Polycom, Snom, Mitel, Aastra, Grandstream & Linksys phones
4. AJAX-based Administration
5. User web portal accessible from mobile phone, with mobile bridging.

(text lifted from www.voiceroute.org with only light editing)

Open source community site: http://www.voiceroute.org
Commercial version: http://www.voiceroute.net