[btdmaster]

Are they deliberately getting their modifications under an pseudo-incompatible* license? This is the only reasonable explanation I can think of.

* IANAL. Although Apache 2.0 and MIT are compatible, using a different license makes it awkward for changes to be merged upstream.

[ognarb]

The biggest change between Apache 2.0 and MIT are related to patents. INAL but the Apache 2.0 is a lot more safe in this aspect.