Can I ask people if a similar program already exists? If not, any ideas where to ask? It is something that people might use a certain vocabulary for, but maybe I don't know that vocabulary, so it is kind of hard to search for it.
Is it a programming related program, like a parser, a library or some other development tool?
If it is, it should be fine on SO.
Otherwise, I would say Superuser.com is the right choice.