Reply I've gotten from Texas Nerd House:

Yes, at http://emulator.pdp-11.org.ru/DVK/distr/ and see http://zx-pk.ru/threads/18351-emulyator-dvk.html for the forums.

I had to make a small tweak in the config of mine before it would boot, but I can't remember what exactly. If they can't figure it out, I could share my config.

Also it's not so straightforward to use, like a regular computer is: you boot into the ODT (octal debugging terminal) where you must either type in the machine code for a driver or specify one at the command line. In the emulator, he should type "BMX0" or "BMY0" or "BDW0" to load from any of the emulated disks; this will bring him to RT-11 OS where then he can type in something like "run tetris".