Ask HN: What are the best enterprise opensource Portal/CMS

Does anyone have any recommendations for implementing large-scale Web-based opensource CMS solutions?

Does anyone have thoughts around building out a more content-driven site using a "Portal" platform?

We are looking at building out a site similar to: ey.com, liveunited.org, gatesfoundation.org, cisco.com

Liferay (liferay.com) looks interesting however it is at its core a Portal platform which I am leery about building a mostly content-based platform, with some "social" functionality.