Download of LiteLoader 1.12.2 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free Mac application is a product of Adam Mummery-Smith. The software is included in Games. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software.
From the developer:
LiteLoader is a lightweight mod loader for Minecraft designed to provide simple, high-performance and reliable loader functionality for mods which don't need to modify game mechanics. It is designed to run alongside Minecraft Forge and Forge Mod Loader (FML) and LiteLoader mods will virtually never conflict with Forge mods.
You may want to check out more Mac applications, such as zeroN64, which might be related to LiteLoader.