Additionally, one of the language designers, Sylvan Clebsch, now works at Microsoft Research, so in a way Microsoft is also sponsoring the work on Pony.
I'm the VP of Engineering at Wallaroo Labs. Pony existed prior to Wallaroo Labs using it, but we have been very instrumental in pushing the language and runtime forward. We've contributed a lot of code to Pony.
If you are interested in the early history of Pony you can learn more from Sylvan's post here:
https://www.ponylang.io/blog/2017/05/an-early-history-of-pon...
He definitely isn't churning out tons of code for Pony these days. He is still, however, actively involved. From time to time, big new things from him show up. The latest one has been cooking for several months now and probably won't show up for a few more.