I used Bencode to encode messages for a presence and messaging system. Easy to write parsers for, binary safe, worked well overall. Probably the only real issue

I used Bencode to encode messages for a presence and messaging system. Easy to write parsers for, binary safe, worked well overall. Probably the only real issue was that the sizes of lists and dictionaries aren't known in advance. This actually is a benefit in some streaming contexts, but calls for caution when dealing with user supplied data. JSON has the same problem, for what it's worth.