The business implications of this are interesting. In my opinion this is another warning shot that if you don't open source your business someone else may just do it for you. If I was LiveFyre or Disqus I'd definitely be nervous about Mozilla coming into my space and building competing software with a commitment from two of the big players to use it. Leveraging open source by adding value via services or premium offerings has been a very powerful business model in the last few years.

They've done this previously with DocumentCloud:

http://www.knightfoundation.org/grants/20083268/

Which is still active and widely used among news organizations, but is probably better known for the JavaScript libraries that were abstracted from it during development: Underscore and Backbone

Also CoffeeScript.

Coffeescript was not funded by the Knight Foundation and was not developed for DocumentCloud.

Jeremy started Coffeescript as a personal project in his off time while building out DocumentCloud/Backbone/Underscore.

It was still funded by them, albeit indirectly :P Actually a great example of the kinds of halo effects you can get from funding open source development

Is there not a comment platform that already exists?

Seems strange if there isn't...

Apart from the various (IMHO horrible) php bb forum workalikes, I'm only aware of Discourse:

http://www.discourse.org/

[edit: Personally I'd love to see this end up being a real effort to make a decent web front-end to/for (and an interface for integrating into web sites) mailman3. I'm sick of half-assed email integration for discussion sites (with poor support for non-html mail).

Still, as most news sites have a vested interest in forcing (web) views (for ad imprints) when none are really needed for viewing the content or participating in the discussion -- I doubt we'll get that.]

A good list of comment platforms is here: http://www.elegantthemes.com/blog/resources/using-alternate-...

The two most popular that I've seen are facebook comments and disqus.

Those are two of the biggest reasons I don't comment on many such sites, ever. Of course, I must be one of the last three technical people who has never had a Facebook account, despite having known about them since the days you needed a .EDU address to sign up.

They do seem the most popular. Neither is open source, sadly.

WashPo was using RealTidBits, now I think they're using LiveFyre (who bought RealTidBits).