Thrift is a lightweight, language-independent software stack with an
associated code generation mechanism for RPC.  Thrift provides clean
abstractions for data transport, data serialization, and application
level processing.  The code generation system takes a simple definition
language as its input and generates code across programming languages
that uses the abstracted stack to build interoperable RPC clients and
servers.

Thrift is specifically designed to support non-atomic version changes
across client and server code.

WWW: http://thrift.apache.org/