They're fairly clearly labelled and categorized. Might be easier to build a frontend to their open Public Domain data rather than asking everyone to re-submit their projects: https://github.com/bevry/staticsitegenerators-list/
As far as I can see there's no categorization. The only way to find the list of actual static site generators is to read through the description of each of them. And since some don't have descriptions, the only way to know for sure is to visit their website and try to read through the docs to figure out.
That said it's a great list of tools around static web-tech - just not super useful if you're strictly looking for static site generators.
There are License and Language keys for most entries. Sounds like you want to filter out the Commercial and Web ones. If you find any that aren't categorized properly, I'm sure they'd appreciate a PR.
