https://en.wikipedia.org/wiki/Actor_model

AIUI I wouldn’t say that everything in Holochain to date has been described as an actor, e.g. the DHT, but I suppose that could change.

Why Rust? https://www.rust-lang.org/. Rust empowers programmers to write fast, light, memory-safe, concurrent code, with the ability to write low-level code as well as having abstractions and generics like in a high-level language. It is better suited for long-term construction and maintenance of complex projects, while it also works well for simple ones. While Wasm aims to eventually support many or all languages, it’s initial focus has been on C++ support, then Rust. Go doesn’t achieve the same level of flexibility, empowerment and strengths.