Version 0.5.9 release contains the following fixes/improvements.

= New Features =
 * Attended call transfer implementation (Replaces support, RFC 3515).
 * Major addition to support DNS SRV resolution in PJSIP:
   * Implemented generic asynchronous DNS resolution engine in PJLIB-UTIL: [http://www.pjsip.org/pjlib-util/docs/html/group__PJ__DNS__RESOLVER.htm]
   * Implemented SRV support in PJSIP: [http://www.pjsip.org/pjsip/docs/html/group__PJSIP__RESOLVE.htm]
 * MP3 file recording [contributed by Toni Rutar]


= Improvements =
 * the echo canceller seems to work and it's now enabled by default on PJSUA-API
 * Speex source codes updated to their latest SVN version (version later than 1.2beta1)
 * added pj_shutdown() and pj_atexit() to release internal handles allocated by libraries (important for Symbian)
 * Add pjsip_regc_add_headers() APi to set headers to be added to the REGISTER request. This solves the problem where headers registered in the initial REGISTER request (such as User-Agent header) are not sent in subsequent reregistration request.
 * Improve call transfer handling in PJSUA-API (not to disconnect call until call transfer completes)
 * Improvements in audio device support:
   * Updated PortAudio to latest version for Mac (OSX 10.4 compatibility)
   * PJSUA-API will try to use other sample rates when it fails to open the device
   * Better support for opening different sound devices.
 * Added support for specifying IP address in PJSUA-LIB/pjsua.


= Bug Fixes =
 * Fixed bug in SIP parser: clone_data member of message body is not set.
 * Added checking for clock rate mismatch in PJMEDIA master port.
 * fixed many memory and handle leaks (there is no single leak now!)
 * fixed SIP message leak when transport immediately fails to send the message
 * Fixed sound device ID bug: application was unable to use device ID zero because this caused pasound.c to autodetect default device
 * Removed duplicated stun.o in pjlib-util Makefile
 * Fixed overflow bug in conference.c causing cracking noise (thanks Norman Franke)
 * Removed multiple Via headers checking in transport, as proxies will receive multiple Via headers.
 * Fixed bug in log length calculation (null character was included) [thanks Klaus Darilion]
 * Fixed missing pj_snd_get_info() in nullsound.c
 * Changed pasound.c to handle situation when NULL is passed as input/output buffer by PortAudio
 * Fixed typos in pj_*int*_t's comments [thanks Tomasz Ostrowski]
 * Removed -DNDEBUG from default CFLAGS [thanks Olivier Gournet]
 * Fixed compilation errors when threading is disabled (PJ_HAS_THREADS=0) and safe ioqueue unregistration is disabled (PJ_IOQUEUE_HAS_SAFE_UNREG=0).
 * Fixed compilation error in tone generator when using fixed point.
 * and many others