WebComponents are based on a collection of proposed web standards that are still being implemented by browser vendors. Its not something by Mozilla. You can learn more about the current direction and updates regarding Web Components in this blog post https://hacks.mozilla.org/2014/12/mozilla-and-web-components...

As for Brick, it is mostly made by people from the Apps team and last time I checked it was going thru a rewrite to base it on platform.js instead of x-tags. You can check with someone from that team on #apps on irc.mozilla.org. Brick is not research, it is just a collection of Web Components.