As of a few minutes ago, https://play.rust-lang.org/ is now powered by the Integer 32 playground implementation! Notably, that means you can use some selected crates! Here’s an example that uses the regex crate.
Specifically, the top 100 downloaded crates of all time are available (edit: as well as their dependencies, when possible). There’s some notion of switching to the top 100 most recently downloaded crates, but that requires changes to crates.io first. We are avoiding hand-selecting any crates to reduce any kinds of favoritism.
This is intended to be a drop-in replacement for the previous playground, so hopefully you won’t notice much other than some small UI differences (and those sweet crates!). Please swing by the GitHub repo and open an issue if there’s a feature you really need or miss! I’ll be removing the “alternate” qualifier from the UI soon, I promise