Can I place restrictions on public domain software that I modify. I want to make closed source but freely available binary

Question

Can I place restrictions on public domain software that I modify.
I want to make closed source but freely available binary.

Answer 1

Yes, you can use public domain code in your closed-source application without any problem.

You cannot place restrictions on that public domain code in the sense that you forbid others from obtaining it as well and using or modifying it. But you are under no obligation at all to provide that public domain code nor do you have to tell anyone that you are using it.