Performance improvements in Python Protocol Buffers

protobuf‘s Python implementation has been known for its slowness, but that might be changing. From a 2010-11-01 changelog:

  Python
  * Added an experimental  C++ implementation for Python messages via a Python
    extension. Implementation type is controlled by an environment variable
    PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION (valid values: "cpp" and "python")
    The default value is currently "python" but will be changed to "cpp" in
    future release.
  * Improved performance on message instantiation significantly.
    Most of the work on message instantiation is done just once per message
    class, instead of once per message instance.
  * Improved performance on text message parsing.

– http://code.google.com/p/protobuf/source/detail?r=349

Also, if you like Protocol Buffers and JSON, check out Protojson.