License:
The Soviet code is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) License. Be well aware of what that means for your code before you use this. It's the people's code.
Note that there are several promotional images from the former Soviet Union. They will have their own copyrights. The CC BY-NC-SA license does not include those files, and the derivative works may be affected by the original image's copyright. Use at your own risk.