UBB Systems purchased UBB.Threads from Rick Baker in June of 2011, which would have been version 7.5.6 (Rick traded his stock options with Groupee for UBB.threads on January 1, 2010 which would have been version v7.5.4). Since January of 2015, principle development on UBB.Threads is done by
UBBDev (versions 7.5.9+), aka myself and id242.
BTW, Rick wasn't the sole person behind UBB.threads, under Groupee he worked with Charles Capps and under David Dreezer; so when you get down to "brass tax" there are quite a few hands that've been in UBB.threads.
Plus, when you get down to where ideas and features magically appeared, you'll note that features have been plucked from 3rd party developers from UBBDev since the 90's.