In this gist I'll explain how I feel about others forking my mods, when it's ok and when I'd prefer it not be done. As most of my mods use open licenses such as the MIT and Apache license I have very little legal power to control forks, but I recommend you follow these guidelines regardless to keep a good relation with me and allow future collaboration.
If you want to fork my mods to play around with the code and learn, then feel free to do so without explict permission. You're also free to fork my mods if you do so intending to contribute to the original with a pull request, however, I recommend you discuss the changes you want to contribute with be beforehand. This allows me to know what you are doing so that I don't accidentally do the same work. Contacting me also helps you make better contributions as I can give recommendations on how thing should be done most efficently.
If you want to fork one of my projects and publish that fork without contributing back I a