I have no idea how many people are even interested here, but anyway. I've been trying to make a new (external) server browser, but haven't even gotten past what should be step 1 - getting the list of servers. Getting info from a server whose address you know is quite easy, but that's not going to help me at the moment.
I wrote a more detailed post about this on Reddit, feel free to answer here if you think you can help, it would be greatly appreciated. The post is a bit wall-of-text-y, but the most important parts are highlighted.