It's a surprisingly readable doc, check it out [0]. Compared to protobufs, it's much more concerned with being more fixed width, word aligned, efficient copy-f

It's a surprisingly readable doc, check it out [0]. Compared to protobufs, it's much more concerned with being more fixed width, word aligned, efficient copy-free in-memory accessable. Proto3 spends a lot of effort compressing ints on one hand but remaining flexible and allowing fields to be optional on the other. On top of all that, there's a good deal that's specific to it's kernel, Zircon, it's permission/capabilities model, and how these messages interact with their syscalls. I'd imagine these kinda details are going to matter a lot for a microkernel. I don't know it as deeply but I'd say it's much closer to cap'n proto. Not sure who uses that though! [0]: https://fuchsia.dev/fuchsia-src/reference/fidl/language/wire-format https://fuchsia.dev/fuchsia-src/reference/fidl/language/wire...