I used Kaitai for parsing and reverse engineering a binary format that does have some documentation but it's mostly wrapped in a lot of legal mumbo jumbo. Total

I used Kaitai for parsing and reverse engineering a binary format that does have some documentation but it's mostly wrapped in a lot of legal mumbo jumbo. Total novice to parsing binary files, looked very intimidating, but with Kaitai IDE I was able to pick it up quickly and had some wonderful results. It has some limitations (already mentioned here), but still very powerful tool. There is a (relatively small) community active on the gitter.im Lobby that was very welcoming and helpful when I got stuck at a problem. I can't recommend it enough, even (or especially)if you are a novice. It looks daunting, but I found it surprisingly nice.