Do you have any personal experience in doing so? They seem like tempting projects from the outset, but getting started with some clear goals in mind, alongside philosophical/idealistic differences from what's already out there so you're not simply rewriting something for the sake of it has prevented me from getting too far down a particular rabbit-hole.
My first php framework was something called php4gl back before ruby on rails was created. It used the command line to bake controllers and such. Just a private project never released. Lost the code now!
I also wrote another couple more php frameworks. I used one for all my personal side projects. And I wrote a couple for day jobs website over the years.
Actually it wasn't until Laravel came out that I was convinced NOT to write or use my own php framework ;)
So, now I've stopped writing php frameworks. But, I still write a CSS component framework from scratch for every project.
I wrote a really quirky javascript framework called Double Dollar that worked using a kernel pattern. Anyone I showed it to thought it was nuts. I abandoned it and now just use jquery for projects I work on like https://nugget.one
Probably the most sucessfull open source project I created was ezSQL. Wordpress ended up using it as their original database class and then as the API interface for their current wpdb database class. I think a lot of people probably curse me for that ;)
