D-Bus bindings for Rust
D-Bus is a message bus, and is mainly used in Linux for communication between processes. It is present by default on almost every Linux distribution out there, and runs in two instances - one per session, and one system-wide.
In addition to the API documentation, which you're currently reading, you might want to look in the examples directory, which contains many examples and an argument guide. README.md also contain a few quick "getting started" examples.
In addition to this crate, there are two companion crates, dbus-codegen for generating Rust code from D-Bus introspection data, and dbus-tokio for integrating D-Bus with Tokio. However, at the time of this writing, these are far less mature than this crate.