What would you do in case someone stole your idea and a couple of months after your release - made a release of a likely software unit, but under a different name? Are there any ways to punish such a thief or prove you have right in this case?
It really depends on what the idea was all about. Remember lots of people have similar ideas...what you think is unique may have been thought of before. I have seen it happen to me... there has been at least 3 times in the last two years I came up with a really brilliant idea for a piece of software/product and once I started looking into it, it has been created already. In this case perhaps the person didn't do his research and went ahead, creating the product like yours without knowing. It does happen.
No, the software was created by us and then resold by one of our customers as their own product (a little modified). That's what I meant