[brundolf]

> Not sure how a ruby version manager in rust will help - the only thing that's slow with asdf-ruby is building any given version of ruby

Worth noting that there are benefits to doing a CLI in Rust other than raw processing speed:

1) Type system

2) Compared with C/C++:

2a) Safety

2b) Trivial cross-platform builds with no runtime dependencies

2c) Stellar package ecosystem to build on, including powerful CL arguments handling

3) Compared with interpreted languages

3a) No runtime dependencies

3b) Fast cold-start because it's a native binary

Of course none of these makes it the automatic winner, and several don't really apply when compared to shell scripts. But the type safety does, and another big one that comes to mind is trivial Windows support, which from a quick glance asdf doesn't seem to have.