Scripting Layer for Android (SL4A) brings scripting languages to Android by allowing you to edit and execute scripts and interactive interpreters directly on the Android device. These scripts have access to many of the APIs available to full-fledged Android applications, but with a greatly simplified interface that makes it easy to get things done.
Scripts can be run interactively in a terminal and in the background. Python, Perl, JRuby, Lua, BeanShell, JavaScript, Tcl, and shell are currently supported, and we're planning to add more. See the SL4A Video Help playlist on YouTube for various demonstrations of SL4A's features.
SL4A is designed for developers and is alpha quality software.