If you want to check out their current editor, $20/month gets you access to the editor and the full C++ source for the engine. You can even cancel the subscription and keep using it if you don't need updates.
I doubt it'll be included with the new UT (since that's going to be free), but it's a pretty impressive toolset.
I doubt it'll be included with the new UT (since that's going to be free), but it's a pretty impressive toolset.