Sofia-SIP is a SIP user agent library, compliant with the IETF RFC3261 specification. It can be used as a building block for SIP client software for uses such as VoIP, IM, and many other real-time and person-to-person communication services. The primary target platform is GNU/Linux. Sofia-SIP is based on a SIP stack developed at the Nokia Research Center.
Speex is a patent-free compression format designed especially for speech. It is specialized for voice communications at low bit-rates in the 2-45 kbps range. Possible applications include Voice over IP (VoIP), Internet audio streaming, audio books, and archiving of speech data (e.g. voice mail).
Spring ME is a version of ME that not only runs on your cell phone, but also on any other Java platform not supporting reflection. It is to Java ME what Spring is to Java SE and Java EE, which is indicated by the name. However, the "ME" (Micro Edition) suffix not only refers to the platform it supports. It also refers to the size of the runtime, which is pretty minimal. In fact, it's pretty much non-existent, and therefore ideal for situations in which you cannot afford the sheer size of the traditional Spring runtime.