speedrunner

Most of a command-line tool's start-up goes into loading the interpreter's modules before it does any work. speedrunner keeps each tool loaded in a per-user daemon and serves every call from a fork of it, with the same output, exit code, environment and terminal as a normal run. If it can't serve a call, it runs the tool normally.

There is no per-tool setup: prefix a command with srr, or enroll it once in zsh or bash, where the daemon warms up while you type the command name. It works with tools as they are installed, such as aws, black, poetry, rubocop, rspec, artisan, composer and eslint.

Measured on 96 commands, the median gain is x4.9, with identical output. It only saves start-up time, so it helps short commands called often, in a shell, an editor or a script. It is a single static binary written in Rust, for Linux and macOS.