Register Page - What are these sites using?

Perusing the "10 Latest Buddypress..." article here on WPMU and i've seen many of the sites that use a very custom registration page as opposed to the built in WP one.

Is this a WPMU plugin they are using or what?

http://helloecoliving.com/join-hello

http://rideoregonride.com/register/

Just two samples from sites on the list at https://premium.wpmudev.org/blog/10-of-the-latest-and-greatest-inspirational-buddypress-sites/