The Open Source Teaching Project (OSTP) is an attempt to apply a variant of the successful open source software approach to the development of educational materials. Open source software is software licensed in such a way as to allow anyone the right to modify and use it. From such a simple premise, a whole industry has arisen, most notably in the form of the wealth of companies supporting GNU/Linux. However, open source content initiatives, at least in the educational context, have so far failed to achieve popular, widespread success to the extent that open source software has. This research note briefly describes a development model based on the open source software phenomenon, identifying those key features that are potentially generalizable to other industries; in particular, the creation of 'preversioned', reusable components, and the demonstration that giving away intellectual property can make commercial sense. These aspects are developed in the context of the production and distribution of educational materials, and from this identify the "hard problems" (i.e., the major research issues) that have been identified within the OSTP are identified. Includes one figure. An appendix includes "The Proposed e-University (Notes for the OSTP on HEFCE document 44/00)." (Author)