The Second Life physics engine Havok2 is being upgraded to Havok4. The upgrade to the Second Life physics engine should provide better and more realistic body dynamics and collisions. The upgrade to Havok 4 physics engine in Second Life will supposidly increase sim stability and reduce some lag frequently found in the virtual world. Havok 4 is currently being beta tested and can be previewed by the public. The physics similuator should crash less and vertical simulation will be increased by 1024 meters.