Every build system has a different approach to handling the tasks that you need to run often for your project. With make each task would become a different recipe. With npm you would use npm run. With cargo the most common tasks are a subcommand. But then say you have an uncommon thing you need to do a lot, or you need to pass an extra argument to cargo run every time, then cargo can't help you with that. So I often find myself creating a makefile for my Rust projects. But then if I want to be able to pass arguments to the recipes, make doesn't allow for that. The whole thing is a big mess.
run is intended to be a more unified solution to the common scenario of "I have some tasks that I want to run often in this directory". The idea is that you write your tasks as regular bash functions in a file named runfile in the directory where you plan to run them. Then you use run to run tasks from your runfile. If you execute run with no arguments then it runs the task called run, like make does with the first recipe. run also lets you pass arguments to your tasks.
run is an 11 line bash script. Installation is easy, you can just copy and paste the script into a file on your path. This command will do it for you:
curl https://raw.githubusercontent.com/akriegman/run/main/run >~/bin/run ; chmod +x ~/bin/runOr, if you have a project with a runfile but you don't have run installed, you just run the tasks as ordinary bash functions, for example:
$ . runfile
$ runThis has the disadvantage of polluting your bash session.
Here's an example runfile from a project of mine: https://github.com/akriegman/electro/blob/main/runfile
Including a hashbang #!/bin/bash on the first line of your runfile may help your editor recognize your runfile as bash for syntax highlighting and formatting. This hashbang will not be used with either invocation method, however.
Many people prefer Makefile over makefile because it appears higher in most file explorers. As a terminal user, this doesn't help me as ls mixes capital and lowercase files. Further, Makefile is harder to type and I find makefile more aesthetic. For these reasons I prefer lowercase, and I guess for simplicity run only acknowledges runfiles, not Runfiles.
https://github.com/TekWizely/run and https://github.com/simpzan/run had the same idea as me with the same name. My version is the most minimal of the three, but if you want more features then check them out.