SQL Server 2008 comes in seven basic editions: Enterprise Edition, Standard Edition, Web Edition, Workgroup Edition, Express, Express with Advanced Services, and Developer Edition. All these editions are available in both x86 and x64 versions. However, each edition offers different feature sets and pricing. Let’s look at how the editions differ.

SQL Server 2008 Enterprise and Developer Editions
Targeted toward large, enterprise-level organizations, SQL Server 2008 Enterprise Edition supports up to 64 CPUs and an OS maximum of 2TB of RAM. It also has support for Hot Add RAM and Hot Add CPU, 50 instances, data partitioning, data compression, failover clustering support for up to 16 nodes, database mirroring, database snapshots, fast recovery, online indexing, change data capture (CDC), SQL Server Integration Services (SSIS) advanced transformation, SQL Server Analysis Services (SSAS) writeback dimensions, and SQL Server Reporting Services (SSRS) infinite click-through and scale-out web farms. Pricing for SQL Server 2008 Enterprise Edition is $24,999 per processor or $13,969 per server, including 25 CALs. Developer Edition has the same feature set as Enterprise Edition but is licensed only for development work ($50 per license) and can’t be used in production.

SQL Server 2008 Standard Edition
Targeted toward midsized businesses, SQL Server 2008 Standard Edition includes support for up to four CPUs, an OS maximum of 2TB of RAM, and supports up to 16 instances. Standard Edition includes all the basic business intelligence (BI) functionality, including SSIS, SSAS, and SSRS. Standard Edition is priced at $5,999 per processor or $1,849 per server with five CALs.

SQL Server 2008 Web Edition
This new addition to the SQL Server product line is targeted toward web-hosting providers. It provides support for up to four CPUs, an OS maximum of 2TB of RAM, and up to 16 instances. Web edition has SSRS but not SSIS or SSAS and is licensed for $15 per processor per month.

SQL Server 2008 Workgroup Edition
Workgroup Edition is designed with an eye toward small businesses and departmental installations. Workgroup Edition supports up to two CPUs, can use a maximum of 4GB of RAM, and supports up to 16 instances. It provides relational database support and SSRS but lacks SSAS and SSIS. Workgroup Edition is licensed for $3,899 per processor or $739 per server, including five CALs.

SQL Server 2008 Express and Express with Advanced Services
Targeted toward developers, SQL Server 2008 Express is suitable for small businesses. It’s also used as the built-in database for many other Microsoft applications, such as SharePoint and the Microsoft System Center suite. Express Edition supports 1 CPU, up to 1GB of RAM, and 16 instances.

Express with Advanced Services Edition extends the basic relational database capabilities of SQL Server 2008 Express by including SSRS and SQL Server Management Studio Basic, which can be used to mange SQL Server Express systems. SQL Server 2008 Express and SQL Server 2008 Express with Advanced Services are no-cost downloads; you can download Express here and Express with Advanced Services here.

There’s one more edition: SQL Server Compact Edition 3.5. However, this product uses a different code base than the other SQL Server editions. Compact Edition is 32-bit only and is intended primarily as a small footprint, in-process database for mobile and desktop applications.