I like Annotate a lot, but have not used the AROS version but I imagine it's extremely similar to the OS4 version. I'm extremely happy with Annotate, powerful and runs without a hitch for me.
CygnusED is the classic pick for text editors, but unsure if it's available on AROS. It's still my fave by far, but I've yet to purchase it for OS4 due to the fact I can't do so via the internet in a direct delivery fashion, it's only sold via web and snail mailed AFAIK. CED is the best text editor I've ever used on any platform, tbh.