It's a character encoding detector to be used when consuming encoding-unlabeled legacy Web content. If your app needs to consume the long tail of legacy Web content, this crate is probably of interest to you. If you don't need it, you should be happy about not needing it.
This is a sad day for the web, even if it was a bit easy to predict something like this happening.
|Mozilla \ Google||No Autodetect||Autodetect|
|No autodetect||Yay! Simpler, more predictable web!||Chrome poaches users from Firefox. Eats the cost of maintaining ced to do so.|
|Autodetect||Firefox poaches users from Chrome. Eats the cost of maintaining chardetng to do so.||Oh no! Autodetect is part of the web forever!|
In any case, it's nice to see that Mozilla has truly committed to developing new and improved Firefox features in Rust.