If anyone's interested, I just added the source to a CHIP-8/SCHIP emulator I wrote in Java/OpenGL (through LWJGL) waaay back in the day. It's got a unique rendering style (screenshot at repository) and a hack to try and smooth out the flicker from XOR rendering you get in the original.
It might take a minute to get it set up with an old version of lwjgl, but at least the source is there for now. I'll try and get it working and commit the necessary lib files later today, but thought I'd at least make the source available for now.
I see that you used Cowgod's Chip8 reference. That document gets a number of details subtly wrong. In particular, shift and load/store instructions. I strongly encourage referring to the more accurate "Mastering Chip8":
Awesome. I didn't know. I'm going to try to get as far as I can using my rudimentary knowledge of how an emulator is supposed to behave and a reference to opcodes and such.
Sure. If it's a question that might be relevant to Octo (especially things to do with quirks modes or programming techniques or ergonomics) you can ask a question on the Octo Github page or mailing list.
Despite the widespread cursory interest in CHIP-8, as exemplified in all the VM implementations in this comment thread alone, there isn't currently any sort of centralized community for it. The users and developers of Octo are open to furnishing that to the extent they're able.
https://www.youtube.com/watch?v=B-FROP4pYe0 (2014)
https://www.youtube.com/watch?v=fxPoscaB8aE (2015)