When you use SharePoint to set up an extranet, you first need to decide whether to use Windows SharePoint Services (WSS) 3.0 or Microsoft Office Share- Point Server (MOSS) 2007. If WSS will adequately fulfill your specific requirements (in my case, security, ease of use, document management, search, change notification, lists), then it would be the logical choice. If you need functionality that WSS doesn’t provide, then you’ll want to use MOSS.
For example, in WSS, search is merely a service for indexing a content database. MOSS search can index a variety of sources, which would allow external users to search across multiple site collections (extranets). If this is a must-have requirement for your external users, you should consider MOSS. However, if your internal users are the only ones with a need for this functionality, consider deploying MOSS on your intranet instead of on your extranet, and then point the search index crawler to your extranet’s site collections.
Although WSS is less expensive to license than MOSS, this initial expense likely doesn’t represent the bulk of your licensing costs. SharePoint can be deployed in such a variety of ways that licensing of all involved servers becomes quite complicated. For the purposes of an extranet, you might also need to purchase an external connector license. Ultimately, you might have to discuss these details with a Microsoft licensing representative. To get a head start on your licensing research, read the Office&SharePoint Pro.com articles “Licensing Windows SharePoint Services for the Extranets” (www.officesharepointpro.com/content/1924/License-to-Fill--Licensing-Windows-SharePoint-Services-for-the-Extranet-.aspx) and “Licensing Windows SharePoint Services” (www.officesharepointpro.com/content/1925/Licensing-Windows-Share-Point-Services-.aspx).