Free IMS Clients

• IMSDroid, for Android
• iDoubs, for iOS (iPhone, iPad and iPod Touch)
• The UCT IMS Client is available under the GPL (open source)
• The IMS Communicator is available under the GPL (open source)
• FOKUS' OpenIC (Open IMS Client) is available only commercially. Yet, there is also a free binary OpenIC_Lite version available right here

The 3Gdb Home Subscriber Server(HSS)

This is an implementation of the HSS network element within an IP Multimedia Subsystem (IMS) Core Network (CN).
This project implements the (IMS) database schema described in 23.008 Subscriber Data, the procedures in 29.228 Signaling and the algorithms in 35.206 MILENAGE. It is based upon Release 7.
It is represented below (red background) inside an IMS Core Network.

Another well-known HSS: FOKUS Home Subscriber Server (FHoSS), used in OpenIMSCore.

Reference: http://code.google.com/p/hss/
For more information visit http://www.3gdb.org/doc/overview-summary.html

New Version of UCT IMS Client

The latest version of the UCT IMS Client v. 1.0.12 is now available for download. The main new features are support of MSRP (only message transfer support and not yet fully compatible with the RFC 4975), RTSP (I haven’t tested this feature so all feedbacks will be useful) and EPG for UCT advanced IPTv.