My ACM papers are published in full on my website. Not preprints. In fact thats the only reason I have a website, just in case someone actually wants to read them.
The copyright agreement (actually copyright assignment/transfer) with ACM has had a carve-out for this case in it for a while, but it has to be a personal website.
I thought it was more liberal than that but there was always a “preprint” exemption that would get you around it.