There is only one file type that uses the .LITEMOD extension:
Minecraft LiteLoader Mod File
File used by Minecraft, a sandbox game that lets users build a world by creating and destroying resources; contains modifications to aspects of Minecraft, such as mini maps and in-game chat functionality.
LITEMOD files require the LiteLoader API for installation. LITEMOD files should be placed in the "mods" folder, which is located inside the ".minecraft" folder. If there is no "mods" folder, create one. Once installed, LITEMOD files are designed to not conflict with other installed mods and mod loaders, such as Minecraft Forge.
NOTE: When downloading LITEMOD files, your browser may detect the file as a .ZIP file and give it a "zip" extension. This will prevent the mod from properly working, so rename the extension to "litemod" before placing it in the "mods" folder.
Updated: January 2, 2014