LÖVE engine is a free, open source 2D game library for Lua programming language.
Actually, LÖVE is more than a simple 2D graphics library since it offers many features such as sounds support, threading, timers, keyboard, mouse and joystick support, physics, and more.
Additionally, LÖVE is portable to a variety of systems such as Windows, Unix-based and MacOS. As of version 0.10, official Android and iOS support have been added to the library.
The engine is built to be high level enough so the programmer doesn't need to worry about how Lua will handle your code or how the computer will use the bytecode. LÖVE uses LuaJIT.
To play games made with LÖVE you will need the LÖVE binaries installed in your computer, but also, if the programmer gives the option, it is possible to create games that are a standalone executable with the LÖVE executable and the game itself both packed together.