I used to do consulting in Web accessibility. I still do research in other fields of accessibility, chiefly captioning, audio description, subtitling, and dubbing.
I was a freelance writer during the 1990s, with about 400 published articles.
I have written two books thus far:
joeclark.org (where you are right now) is a professional site, you could say, and is home to hundreds of old articles, plus a number of topics with ongoing updating
Check my contact page.