Great suggestion, AlternativeTo.net was crucial during my transition to Linux some years ago and I recommend it even to people on Windows trying to find alterna

Great suggestion, AlternativeTo.net was crucial during my transition to Linux some years ago and I recommend it even to people on Windows trying to find alternatives to commercial software. Although it may not have some obscure software that would be what you are looking for, it's a starting point that can give you some names to help further the search.