A lot of its functionality is unused still, but the goal it to slowly migrate logging functionality to it. There is also a useful progress bar which can be ported over later - it depends on this module. 4c1fa54d10/src/cargo/util/progress.rs
4c1fa54d10/src/cargo/util/progress.rs
To better distinguish the deno_core crate from the executable deno, which will now be called "the cli" internally.