Seems it will have feature to make own kits, but how?
Will there be separate editor?
Yes, there is a quite versatile editor in the sources, and it's quite usable at the moment. The kits we have on the site, is made using the editor.
What you need to do is set up a complete recording environment with a fully mic'ed drumkit, overheads, ambience mics and so on. As many channels as you'd like. Then record each drum at different velocities ranging from very slight hits, to very hard hits. About 30 for each drum / cymbal and also the varieties you want (open hihat, closed hihat, pedal hihat and so on). Then export each drum on all channels, giving you 1 wav per channel per drum. Put them in folder called "Snare" and "Kdrum" and so on. You can call it whatever you'd like, as long as you have all the wavs for one drum in the same folder.
The editor can then load all wavs for one instrument and using a master channel (for instance the snare would use the snare top channel and so on), the editor will cut all hits of all channels into new wavs and export a wav with all the definitions of hit velocities.
A short description I know, and probably not very useful without a video tutorial. But I'll make one, I promise!
It is not available as a binary release for Windows at the moment. But if you run Linux, you can compile it yourself. I'm not sure if it compiles under Windows though.
I will post tutorials for using the editor at some point in the near future.