In small doses, perhaps. After having to maintain some larger M4 macro collections (for Autoconf and the Autoconf Archive), as well as using it in some work pr

In small doses, perhaps. After having to maintain some larger M4 macro collections (for Autoconf and the Autoconf Archive), as well as using it in some work projects for code generation, I'd have to say that maintenance and testing are hard. Quoting can be painful. And it has a number of annoying limitations. In retrospect, I think it was a bad choice, and I wouldn't choose to use it again. Trying to understand what's going on with multiple levels of nested macro expansions is painful, particularly when you can't directly introspect all the intermediate expansions. When it comes to M4 usage within Autoconf, I'd happily see it dropped entirely in favour of shell functions. It's a historical implementation detail which should have been removed over a decade ago.