This paper describes a simple versioning system which we have developed to support collaborative authoring on the WWW. The system provides facilities for versioning pages and allowing readers access to different versions of web pages. We discuss why such a system is needed and present the versioning model which we have developed. This model allows existing web pages to be converted to versioned entities without affecting links to those pages. Central to the model, is a set of access control facilities which allows authors to provide co-authors with access to versions of pages under development. We describe the instantiation of this model and assess our work against the requirements identified in the first part of the paper.