Statamic is a commercial flat-file CMS built on PHP, with Antlers templating, and YAML + Markdown for storing articles and pages (YAML for metadata, Markdown for the content), but no known IndieWeb building blocks support yet, nor IndieWeb examples.
If you know of some please note them here!
- Testimonial preferring Statamic over WordPress: https://twitter.com/Malarkey/status/1085234388076498945
- "I’m a huge fan of Statamic." @Malarkey January 15, 2019