SQL Server Data Tools is a free component of the SQL Server platform and is available for all SQL Server users. It provides a modern database development experience for SQL Server versions 2005 and up as well as SQL Azure.
From the official description: Microsoft SQL Server Data Tools provides an integrated environment for database developers to carry out all their database design work for any SQL Server platform (both on and off premise) within Visual Studio. Database developers can use the SQL Server Object Explorer in VS to easily create or edit database objects and data, or execute queries.
Developers will also appreciate the familiar VS tools we bring to database development, specifically; code navigation, IntelliSense, language support that parallels what is available for C# and VB, platform-specific validation, debugging and declarative editing in the TSQL Editor, as well as a visual Table Designer for both database projects and online database instances.
SSDT can be downloaded from http://msdn.microsoft.com/en-us/data/hh297027