The new Android Runtime, ART, is finally out for testing on developer devices and some kit-kat ROMs. it will be replacing Dalvik, an aging JIT compiler built for compatibility. ART is an AOT compiler, or Ahead-Of-Time. http://www.androidpolice.com/2013/11/06 ... in-kitkat/
ART, which stands for Android Runtime, handles app execution in a fundamentally different way from Dalvik. The current runtime relies on a Just-In-Time (JIT) compiler to interpret bytecode, a generic version of the original application code. In a manner of speaking, apps are only partially compiled by developers, then the resulting code must go through an interpreter on a user's device each and every time it is run. The process involves a lot of overhead and isn't particularly efficient, but the mechanism makes it easy for apps to run on a variety of hardware and architectures. ART is set to change this process by pre-compiling that bytecode into machine language when apps are first installed, turning them into truly native apps. This process is called Ahead-Of-Time (AOT) compilation. By removing the need to spin up a new virtual machine or run interpreted code, startup times can be cut down immensely and ongoing execution will become faster, as well.
Once this is fully implemented and apps have been updated, the android OS as a whole should be more responsive and fluid, apps should load faster and perform better, and battery life should increase noticeably. WIN-WIN.