Tracking development of pjsip, the Open Source SIP, media, and NAT traversal stack/SDK/library for Android, iOS, Windows, Linux, MacOS, RTOS, embedded, and pretty much anything, any device.
Also check PJSIP Documentation site.
After some delay, finally PJSIP version 0.5.10 is released, and it contains new features such as Python language binding for pjsua-api, experimental TLS support, Visual Studio 2005 support, explicit SIP transport binding, and various other enhancements as well as tons of bug fixes.
Download it as usual from http://www.pjsip.org/download.htm.
Here is where we talk about pjsip development in general, and maybe other stuff as well. For the project itself, please go to the main pjsip project website. or pjsip documentation.
PJSIP is backed by Teluu, which provides professional support, additional licensing options, and a network of qualified consultants.
pjsip blog 