Augeas [1] does a decent job of translating various formats into a common AST which you can edit and write back out, but setting this up is often more trouble than just editing/templating whatever config and moving on with your life.
Many new projects go straight for YAML/TOML/JSON/INI as they're widely understood and relatively easy to parse. I think this is as close to standardization as you'll get.
OpenBSD's developers have gone in the other direction, defining domain specific configuration languages for each of their daemons. They're all different, but they look similar enough that it feels like a cohesive system. You can look at the yacc grammar and see how httpd's config [2] got started as a fork of relayd [3].
[2] https://github.com/openbsd/src/blob/master/usr.sbin/httpd/pa...
[3] https://github.com/openbsd/src/blob/master/usr.sbin/relayd/p...
Augeas seems interesting. I'll have to look into it a bit more than my cursory glance at the github issue queue. :)
Thanks!
Works great, even with my laptop, desktop and server sharing the same config. Versioned rollback + nixpkgs has kept me happy for about 4 years with this setup.
That said, someday I need to give NixOS a try.