For servers running in an environment that have both Forge and Bukkit's API installed this mod will proxy all of Forge's PermissionsAPI calls to Bukkit's permission API.

This mod in itself supplies no permission handling system so you will need to install one that supports Bukkit. Also if you install a second mod that implements Forge's Permission Handler it is non-deterministic which one will be loaded first and used (Minecraft will not crash).