Once again, NATIVE INSTRUMENTS raises the bar with KONTAKT 5 the latest version of the industry-leading sampler. KONTAKT 5 takes a bold leap forward with 37 new filters, four new on-board studio effects, updated time-stretching, a new instrument bus system and more. As you will see from the new STUDIO DRUMMER, for example, its a deep-rooted update to the KONTAKT platform, allowing us and you to create even better instruments and more powerful, expressive sounds.
Whats New in 5.5.2:
Fixed a KSP issue causing Kontakt to crash when using set_key_name() under certain circumstances
Group effects can now be changed via KSP without the associated group being selected for editing
The KSP command mf_remove_event() now correctly clears all data
Fixed a KSP issue when using the load_array() command with string arrays, now allowing loading directly from NKRs (mode 2)
Fixed a KSP issue in which the on persistence_changed callback did not complete after loading an instrument via the instrument header
Ableton Live no longer freezes when a track containing Kontakt is automated and frozen
Fixed an issue in Fruity Loops where multiple instances of KONTAKT would cause a crash upon the loading of a project
MIDI CC modulators now work correctly for slots 2-128 of instrument banks
Fixed an issue introduced with 5.5.1 that caused Kontakt to crash when loading bank files
The import version is now present in the About Dialog on all Mac OS versions
Fixed an issue with 5.5.1 that caused Factory Presets to be scanned on each launch

HOme:

http://www.native-instruments.com/en/products/komplete/samplers/kontakt-5/