One of the most easily overlooked aspects of the recent SQL Server 2008 release is SQL Server 2008 Express, which is a freely distributable database that shares the same core relational database engine as the full-featured SQL Server 2008 Standard and Enterprise Editions. SQL Server 2008 Express offers full support for the new SQL Server 2008 data types including Date, Time, Hierarchical, Geospatial and FileStream. It doesn’t support more enterprise-oriented features like the Resource Governor, Transparent Data Encryption, Integration Services or Analysis Services.
One big difference between SQL Server 2008 Express and SQL Server 2005 Express is the fact that the SQL Server 2008 Express includes the Import and Export Wizard, making it much easier to transfer data into and out of SQL Server 2008 Express databases. All of the various editions of SQL Server 2008 Express can run on larger, more powerful systems but they have the same maximum values: 1 CPU, 1 GB of RAM, and a maximum of 4 GB per user database. Each Express edition comes in a 32-bit and 64-bit version.
SQL Server 2008 Express
The most basic database engine and at 61 – 89.1 MB (32-bit or 64-bit), it’s also the smallest download. SQL Server 2008 Express Edition is the right choice for ISVs and application developers needing to include multi-user database services with their applications.
SQL Server 2008 Express with Tools
This edition adds SQL Server Management Studio Basic to SQL Server 2008 Express database services. The Tools edition is a 218.6 - 230.4 MB download and is the right choice for application developers who need basic database management capabilities.
SQL Server Express 2008 with Advanced Services
Weighing in at 502.7 – 546.5 MB, the Advanced Services edition is full-featured and includes all the features in the Tools edition plus support for Full Text Search, Reporting Services, and the Report Designer in the Business Intelligence Developers Studio (BIDS). Advanced Services is the best choice for application developers who need to incorporate Reporting Services reports. However, these Reporting Services capabilities are limited to working with just the local SQL Server Express databases.
You can see a summary of the features in the different SQL Server 2008 Express editions at MSDN. Download the different SQL Server 2008 Express editions for free from Microsoft.