rtx is a polyglot runtime manager (asdf rust clone).

Features:
* asdf-compatible - rtx is compatible with asdf plugins and .tool-versions
  files. It can be used as a drop-in replacement.
* Polyglot - compatible with any language, so no more figuring out how nvm,
  nodenv, pyenv, etc work individually-just use 1 tool.
* Fast - rtx is written in Rust and is very fast. 20x-200x faster than asdf.
* No shims - shims cause problems, they break which, and add overhead. By
  default, rtx does not use them-however you can if you want to.
* Fuzzy matching and aliases - It's enough to just say you want "v18" of node,
  or the "lts" version. rtx will figure out the right version without you
  needing to specify an exact version.
* Arbitrary env vars - Set custom env vars when in a project directory like
  NODE_ENV=production or AWS_PROFILE=staging.