I’ve seen many announced but I don’t know which ones are actually free and publicly accessible through a website. For example there was a russian one called Gigachat and a chinese one by alibaba but I don’t know where to find them. There is ChatSonic but it’s limited so not the kind of option I’m looking for.
If by “free and public” you mean a model and code that you can download and run on your own hardware, there is this one: https://crfm.stanford.edu/2023/03/13/alpaca.html
but if you mean a free service… it looks like their public demo (which was here) is not operating currently. but since it is relatively easy to run, there are probably other alpaca-based services you can find.
There are instructions for how to run your own instance of it here: https://www.howtogeek.com/881317/how-to-run-a-chatgpt-like-ai-on-your-own-pc/