[_ck_]

People should not be registering domain names with any of the Automattic product names in them. While the programs are open source and free, the name is still trademarked by Matt. I doubt he would ever sue little websites but Matt has gently requested this before:

https://wordpress.org/about/domains/

Discussing/promoting the products on your site is one thing, registering domain names with the products entirely different. If you are worried about SEO or promotion you can just use the name as a subdirectory, ie.

my-example-website.com/talkpress/ = okay

my-talkpress-website.com/forums/ = not okay

subdomains might also be a loophole: talkpress.my-example-website.com

And it’s perfectly valid for them to have a commerical product called “TalkPress” that uses the open source bbPress engine. Just like BuddyPress uses WordPress MU and bbPress.