Open source ERP solutions?

I am looking for information about open ERP solutions. Talk at work about
ERP and thinking about proprietary solutions is prodding me to make sure
open source options are considered.

A quick google search resulted in:

http://www.compiere.org
http://www.suse.com/de/partner/search_partners/software_partners/erp/

And a bunch of other links to look at.

As I sift through them, do any of you have suggestions?

Alan