Minecraft Forge is a Minecraft API which allows almost maximum compatibility between other Forge mods.
How to install Minecraft Forge

    Download at the link below.
    Open Minecraft Forge installer.
    Click OK.
    Enjoy

Changelogs:

V9.11.1.953

    Update to Minecraft 1.6.4
Download here: http://3minecraft.com/minecraft-forge-api/