There's also OpenHAB https://www.openhab.org/

OpenHAB is still a bit user unfriendly from my experiences working with it. My existing stuff will talk to Google or Amazon's assistants, but getting OpenHAB to talk back and forth with those devices and Google/Alexa is proving to be a pain in the ass.

I like that cloud access is free, and Alexa integration works for me, although I prefer to keep my automation stuff relatively simple.

For me, I like the OpenHAB scripting, I personally found HomeAssistant to be too complicated to do some things because it was focused on being easy to use. I spent a long time trying to figure out how to get HomeAssistant to do what I wanted with my zwave smart locks, and it was much easier to do it on OpenHAB. So obviously, YMMV based on your preferences and requirements.

I see a lot of people using NodeRed also, which I guess is cool, but I found NodeRed incredibly frustrating compared to writing a script from scratch.

Hass translates to hate in german

This is probably part of why they stopped referring to it as "hass", although many who have been a part of the ecosystem (and probably don't speak German) continue to use the term.

i know, I'm German myself. It's just the acronym used for the service.