Manhattan Integration Framework (MIF), capabilities and licencing.

Manhattan uses Webmethods in Manhattan Integration Framework(MIF), anybody can explain me below points wrt MIF and wM:—
What is MIF capabilities.
Can we do custom development using MIF license.
How MIF is different than using wM.

This question goes to MIF forum (if one available) and its respective documentation for webMethods assets and so did you check there?

Also I think there is no formal framework or adapter OOTB available in wM for MIF but yes custom development wrt MIF API can be done as far I remember from a previous assignment.