A Ruby implementation of Ethereum's Recursive Length Prefix encoding (RLP). You can find the specification of the standard in the Ethereum wiki.
Put it in your Gemfile:
gem 'rlp'
or
gem i rlp
Check tests for examples.
ruby-rlp $ ruby -v -Ilib test/speed.rb
ruby 2.2.2p95 (2015-04-13 revision 50295) [x86_64-linux]
Block serializations / sec: 2318.21
Block deserializations / sec: 1704.61
TX serializations / sec: 30461.76
TX deserializations / sec: 21378.70
pyrlp $ python -V
Python 2.7.11
pyrlp $ PYTHONPATH=. python tests/speed.py
Block serializations / sec: 1225.00
Block deserializations / sec: 1162.01
TX serializations / sec: 16468.41
TX deserializations / sec: 14517.31