I hadn't considered Amazon in this yet, getting this far I was wondering how much GoDaddy has helped with Wordpress or any of it's plugins and such.. It's bee a while, but last I checked they were doing a lot with it and doing some exclusive things perhaps. I see google has been doing some things with wordpress, but I don't trust them and their contributions concern me a lot - working on plugins and themes is fine, but nudging the core would wordpress is a big thing, Automattic does not listen to the little people who use WP as much as I'd like - seeing heavyweights spending time around the base makes me glad there are forks of WP.

far as I remember another big co using mostly WP and I have not seen much from them for contributing back, some place like squarespace or wiz or similar? OF course I have not been looking specifically for plugins and such created by them, and maybe they have contributed to the core - I would not recognize any of the names from them in the list of contributors with releases I have seen.