An Haskell implementation of Google's Protocol Buffers version 2 with an emphasis on simplicity. The implementation consists of a library for encoding and decoding of data and the `protobuf-simple-protoc` executable for generating Haskell types from proto files. In fact, the types that are used in the tests are generated with the following command: In the example below, the CustomType is a Haskell type that was generated with the `protobuf-simple-protoc` executable. The encCustomType function encodes a CustomType into a ByteString. The decCustomType function decodes a ByteString into either a CustomType or an error. The library exposes two modules, Data.ProtoBuf, which is used for encoding and decoding and Data.ProtoBufInt, which is an internal module that is used by the generated types.