“SQL Server 2005 Express October CTP” is the first community technology preview release of SQL Express 2005 post Beta2. The instructions and corresponding CTP executable can be downloaded from here.
CTP is our way of providing the latest bits of SQL Express to the community. However it should be noted that these bits are not as rigorously tested as our Beta2 bits. So, if you are looking for stable and well tested pre-RTM release of SQL Express, please use the beta2 version that can be found here.
Important: Visual Studio 2005 Express team has recently released their October CTP. If you are installing any of the Visual Studio 2005 Express editions (Such as VC++, VC#, VJ#, VB, Web Developer), then you want to make sure to only install SQL Express included as part of the VS 2005 October CTP setup. This is because the SQL Express bits included as part of the VS 2005 Oct CTP has been tested around Visual Studio specific scenarios and works with a more recent version of frameworks than what the SQL Express October CTP uses.
SQL Express Release Program Manager