Open Source ERP???
Everybody knows, right? What are some of the things everybody knows? Well, in control system integration, everybody knows that SAP is the ERP system you must have experience with.
But the truth is that SAP is for big enterprises. Even SAP admits as much, because you have to be over $300 million a year before they'll even talk to you directly. Otherwise, they send you to their integration partners.
But if you have to go to an integration partner to get SAP (read, expensive), wouldn't it be nice...