Tough. The SEC granted an extension of the confidential period.
In May 2010, Facebook and Zynga entered into a developer agreement that, among other things, permitted Facebook to post ads on Zynga game pages, implemented Facebook Credits on Zynga games and generally agreed to work together on technical issues. Since it also dealt with revenue issues, they added their Ireland entities as parties, presumably for tax reasons.
As is often the case with sensitive commercial documents, Facebook requested and received confidential treatment for portions of the agreement when it was filed with the SEC during Facebook’s IPO. Since the confidentiality periods are for a limited time, a registrant must get an extension or file re-file the agreement with the confidential parts added in.
Facebook got an extension, so you will have to wait until at least May 14, 2015 to find out such matters as various notice and time periods and financial and payment terms. In addition, for some reason the identity of the people who signed the agreement is confidential.