Early versions of Minecraft Forge were built on ModLoader by Risugami as the mod loading technology, since it was the mod loading platform of choice at the time. Multiplayer mod support was provided by ModLoaderMP by ScottyDoesKnow (SDK). In early 2012 it was decided to switch to an in-house mod loading solution which would (at least at first) be backward-compatible with ModLoader but would incorporate the functionality provided by ModLoaderMP and remove the dependency on the third-party projects. FML was developed by cpw to fulfill this role.

FML maintained a high level of compatibility with ModLoader mods until Minecraft 1.7, where the ModLoader baggage was finally jettisoned in favour of FML's more flexible and advanced mod platform.

See also: FML on GitHub