Instagib mode with new coilgun model, sound and trail (with recent alpha build of ezQuake for the latest), yawnmode (Molgrum's version of VB's jawnmode), team overlay capabilities, VWEP and many many other new features and bugfixes...

Get it here: KTX website
And here is a documentation to run it: KTX howto

Release notes and Changelog: SF.net release changelog

Note: Some of the features need latest version of MVDsv. I will release a MVDsv beta version a bit later in the day for people unable to compile it for themselves.