Which runtime replaced Dalvik as the default in Android 5.0?

ART, or the Android Runtime, replaced Dalvik as the default runtime in Android 5.0.

The runtime is the system component that executes application code. Dalvik had powered Android apps since the platform’s early releases and used just-in-time compilation to translate bytecode during execution. ART debuted experimentally in Android 4.4 KitKat, where users could select it on supported devices.

With Android 5.0 Lollipop, released in 2014, ART became the standard runtime. Its major design change was ahead-of-time compilation, which compiled more app code during installation. This could improve execution efficiency and reduce processor work at runtime, although installation could take longer and consume more storage.

ART retained compatibility with Android’s application model while adding improved garbage collection, debugging, and performance features. It is not the same thing as the Java Runtime on desktop computers: Android apps use Android’s own runtime and framework APIs.