We have just released rsyslog 5.5.6, a member of the devel branch.
The new release provides exciting performance enhancements: on multicore-machines it can be many times faster than version 5.5.5 (which already was quite fast). Most importantly, the enhancement provides much better scalability, so adding many additional core gains much more speedup than with any previous version.
A new concept of "strgen" modules has been implemented, which permit to use high speed C code as templates. Also, support for malformed "last message repated n times" messages, as emited by some syslogds, has been added in form of a custom message parser.
There are also a couple of bugfixes and minor improvements.
See ChangeLog for more details.
As always, feedback is appreciated.