Hello ams, Welcome.
Currently development is ongoing for 2-way protocols.
X10 has already been implemented using a cm11a (or equiv) and 1 way communication.
Right now, Zwave (2way support being worked on now), Insteon (full 2 way), X10 (1way), PLCBus(full 2way), EIB (?) are supported.
There may be others, check the wiki..