OK, so tonight I was messing around with EnergyXT.
It turns out there finally a multicore version although it's a beta version.
You can get it from here:
[Only registered and activated users can see links. Click here to register]
It's version 3 beta 1. The last stable version was v2.7
You might need to copy libaam.dll from version 2.7's folder into the version 3 beta 1's folder. Also you can copy your xt.lck file from version 2.7's folder into version 3 beta 1's folder. Then everything should work.
I've been testing this out because MIDI input quantize doesn't seem to be working for me in Reaper although it does work for me in EnergyXT. And I must say it works really nicely. I'm able to jam out ideas much faster.
EnergyXT has been around a long time, but it's development is glacier slow for some reason. It's almost vaporware but not quite. But it's still a pretty good DAW in a lot of ways. It's pretty good for loop-based composing. It's piano roll is really easy to use.