My needs are pretty simple - a program that makes grocery lists that I print. groff with the ms macros works very well. I used to use LaTeX but never figured out how to use it without installing gigabytes of stuff. This is my fault - surely I could have learned plain TeX, or learned how to work the TeX distribution to only install the stuff I needed. But ultimately it was just easier to get going with groff.

For those who expect troff to be an ancient relic, Neatroff and Heirloom troff include modern features like microtypography. troff is still great for a lot of applications.

It doesn't have syntax highlighting IIRC

You can hack it with the \m[<color>] escape in groff:

         \m[blue]int\m[] x

Of course, you would use some kind of pre-processor to make this less of a PITA, but it's not inconceivable.