DEX
Dalvik is the process virtual machine (VM) in Google’s Android operating system, which, specifically, executes applications written for Android. This makes Dalvik an integral part of the Android software stack, which is typically used on mobile devices such as mobile phones and tablet computers, as well as more recently on devices such as smart TVs and wearables. Programs are commonly written in Java and compiled to bytecode for the Java virtual machine, which is then translated to Dalvik bytecode and stored in .dex (Dalvik EXecutable) and .odex (Optimized Dalvik EXecutable) files; related terms odex and de-odex are associated with respective bytecode conversions. The compact Dalvik Executable format is designed for systems that are constrained in terms of memory and processor speed. Dalvik is open-source software. It was originally written by Dan Bornstein, who named it after the fishing village of Dalvík in Eyjafjörður, Iceland. An alternative runtime environment called Android Runtime (ART) was included in Android 4.4 “KitKat” as a technology preview. ART replaces Dalvik entirely in Android 5.0 “Lollipop”.
