The document provides an overview of 10 key features to look for in a project extranet. These include: hosting the extranet in the cloud for accessibility; ensuring flexibility of use for different project types; strong security and privacy protections; customizable access privileges; tools for co-authoring and commenting on documents; version control and audit trails; email alerts; vendor support and training; and transparent pay-as-you-go pricing. Choosing a project extranet with these features allows for secure, adaptable and well-supported collaboration with external partners.