The advantages of Web-based document exchange between libraries are just beginning to be systematically explored. This article focuses on general considerations in the development of a Web-based model for electronic document exchange (EDE) in the context of the OpenILL Cooperative's EDEN project. These include an overview of the existing document delivery standard (GEDI) and its relationship to emerging models and a discussion of factors being considered in the development of a Web-based protocol, including document exchange format, application event sequencing, metadata, and security.