hello, I'm the creator of htmx (and originally intercooler) I just released 0.0.4, so htmx is still very young, but it's got a decent test suite: https://htmx.org/test/0.0.4/test/ there is a nice extension mechanism: https://htmx.org/extensions/ and some very rough docs on how to pull off pure HTML animations: https://htmx.org/examples/animations/ happy to answer questions
Edit: Main concern is whether to start a new project now with intercooler or htmx