the upcoming dramatically simpler runtime, smol

...is still not nearly as popular as Tokio, but it does get 210k downloads per month by Lib.rs's count.

They are preparing to cut a 2.0 release.

Of its constituent crates,

• these forbid unsafe code: smol, async-channel, async-net, blocking; and
• these use unsafe code: async-executor, async-fs, async-io, async-lock, async-process, async-task, futures-lite, polling.