Please see my comment to the question. Yes, this is a kind of rant, but because the way you ask the question feels not so nice.
Anyway, I can answer. You just need to read the licenses we use to learn what the terms are:
If I'm not much mistaken, other legitimate open-source licenses can be accepted. So, you can find out enough information on publicly available licenses here by looking at the topics "Open Source", "Open Source License": http://www.codeproject.com/info/Licenses.aspx
Sorry, I did not provide you more exact Wikipeda links, because, at the moment of writing, the Wikipeda site is under maintenance. You can easily find the detailed list of such licenses and all the detail on their terms.
The idea is: you can do derivative work, change whatever you want, but, in most cases, you need to clearly state the attribution
of the original works. In other words, you need to give a credit to people or organization who did their hard job for you. For example, see the explanations in this page of Creative Common licenses:
Good luck, Be Aware,