Protobufs also run anywhere, there are libraries of it ported to almost any machine. When my team was deciding on a binary serialization and RPC communication

Protobufs also run anywhere, there are libraries of it ported to almost any machine. When my team was deciding on a binary serialization and RPC communication format, we needed something that ran on a Cortext m3 with no malloc, and every major phone platform (including WP at the time) and desktop OS. It came down to cap'n proto, and Protobufs. Protobufs runs everywhere. It won.