> while m4 is perfectly fine for simple tasks I don't even want to imagine the layers of opaque and recursive macros you'd end up having to maintain for any mod

> while m4 is perfectly fine for simple tasks I don't even want to imagine the layers of opaque and recursive macros you'd end up having to maintain for any moderately complex project I'm not doing anything too clever with Pug, but there are certainly a bunch of things that it makes quite easy that would otherwise be awkward or complex. Lots of things work really nicely as well: includes, sections, configuration, and it certainly cuts down on typing. I'm absolutely not contemplating a switch from Pug to M4. I just find it interesting that there's this thing that's been hanging around for decades that would do at least a partial job and is still decent for simpler use cases.