As a library writer, it feels a bit strange, but refreshing, to write a program that actually has a main() function. My experience with Rust so far has been threefold: Porting chunks of C to Rust for librsvg - this is all work on librsvg's internals and no users are exposed to it directly. Working on gnome-class, the procedural macro ("a little compiler") to generate GObject boilerplate from Rust.