Bloom is a project mainly written in Python, it's free.
Bloom filter calculations
See http://www.zafar.se/bloom-filter-notes.html for more info.
Depedencies:
murmur3 https://github.com/bkz/murmur3
bitarray http://pypi.python.org/pypi/bitarray
redis-py (optional) https://github.com/andymccurdy/redis-py