Dalvik virtual machine

Introduction
From Wikipedia

The Dalvik virtual machine is a register-based virtual machine, designed and written by Dan Bornstein with contributions from other Google engineers as part of the Android mobile phone platform.

It is optimized for low memory requirements, and is designed to allow multiple VM instances to run at once, relying on the underlying operating system for process isolation, memory management and threading support. Dalvik is often referred to as a Java Virtual Machine, but this is not strictly accurate, as the bytecode on which it operates is not Java bytecode. Instead, a tool named dx, included in the Android SDK, transforms the Java Class files of Java classes compiled by a regular Java compiler into another class file format (the .dex format).

The Dalvik virtual machine was named by Bornstein after the fishing village of Dalvík in Eyjafjörður, Iceland, where some of his ancestors lived.