Wikipedia
MSDE
Microsoft SQL Server Data Engine (MSDE, also Microsoft Data Engine or Microsoft Desktop Engine) is a relational database management system developed by Microsoft. It is a scaled-down version of Microsoft SQL Server 7.0 or 2000 which is free for non-commercial use as well as certain limited commercial use. It was introduced at Microsoft TechEd in May 1999, and was included as part of Microsoft Office 2000 Developer Edition. Its successor, SQL Server Express was released in November 2005. Vendor support of MSDE ended on April 8, 2008.