I see this a lot in the context of computer programs. My original guess was that it stood for something like
meaning something like operating system (i.e. "ПО=OS"), but it seems to appear in the context of general computer programs, not just operating systems, so I really am not sure.
I tried googling it but found it difficult to find a useful result since it has the same spelling as the obviously very common preposition по.
Thank you very much for your time and help -- I really appreciate it!