The Middle School Portal 2: Math and Science Pathways project (MSP2) aims to provide middle school teachers with high-quality materials they can use in the classroom, and to foster greater sharing and communication within the middle school teaching community. The original Middle School Portal was a prototype for the "Pathways" projects funded under the umbrella of the National Science Digital Library (NSDL), and MSP2 remains today entirely funded through NSDL. But the project faces a challenge: How will it cover the costs of operation and development when its current three-year grant runs out in 2011? This case study examines how the leaders of MSP2 are planning for the long-term sustainability of the resource. First, they are exploring a range of revenue-generating activities that build on current strengths of the partner organizations involved in the project. Second, they are considering a "plan B' of building a community-run site that would rely on a free social networking platform, the technical infrastructure of NSDL, and user generated content, a site that its leaders hope could function even with limited paid project staff.