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- Windows SharePoint Services (WSS) v3. This is the free/unlicensed version of SharePoint that is built upon Windows Server 2003/2008, SQL Server 2000/2005, IIS, ASP.Net 2.0, and .NET 2.0/3.0. All you need is a licensed copy of Windows Server 2003 or Windows Server 2008. There are no other licensing costs unless you want the full-fledged version of SQL Server.
- Refer to Microsoft's WSS 3.0 page for more information about this product.
- To download and install WSS 3.0, refer to the WSS 3.0 download page.
- Be aware that WSS 3.0 is free for Windows Server 2003.
- Microsoft Office SharePoint Server (MOSS) 2007. This is the licensed version of SharePoint that is built upon WSS v3. It has two primary versions: MOSS 2007 Standard and MOSS 2007 Enterprise. There are a host of other licensing options as well, such as the ability to use Microsoft Search Server 2008 or Microsoft Search Server 2008 Express with WSS instead of MOSS.
- To download and install a trial version of MOSS 2007, refer to the MOSS 2007 Trial download page.
For more details on the differences between these versions see the following documents from Microsoft:
- How to buy Microsoft Office SharePoint Server 2007
- Microsoft Office SharePoint Server 2007 product comparison download
- Microsoft Enterprise Search Products Comparison
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