For several decades, the Government-Sponsored Enterprises (GSEs), Fannie Mae and Freddie Mac, were the largest players in an American housing finance system that provided effective mortgage financing for many millions of Americans. Since early 2008, the firms' near-insolvency has called their future into question. This paper lays out criteria for evaluating the different proposals for reform of the two firms. We make no recommendations among the proposals, but we do attempt to assess the major advantages and disadvantages of their respective approaches.