This is the C library of Apache Avro (devel/avro).

Apache Avro is a data serialization system which provides:
- Rich data structures.
- A compact, fast, binary data format.
- A container file, to store persistent data.
- Remote procedure call (RPC).
- Simple integration with dynamic languages. Code generation is not required to
  read or write data files nor to use or implement RPC protocols. Code
  generation as an optional optimization, only worth implementing for statically
  typed languages.

WWW: https://avro.apache.org/