[anonova]

Discourse is essentially a SPA (see http://try.discourse.org/) and designed to be public-facing. It does a good job at providing a very bare, lightweight interface for people with JavaScript disabled and, I'm assuming, for web crawlers.

[johnx123-up]

FWIW.. it looks overkill for me

[hiphopyo]

I'd much rather use Forem.

[teh_klev]

...because?

[pa5tabear]

Do they use open source libraries? And otherwise how do they differ from something like Angular?

[Argorak]

Discourse is open source:

https://github.com/discourse/discourse

It uses ember.js with a Rails backend.