Microsoft .NET Framework 3.0 Service Pack 1 provides cumulative roll-up updates for customer reported issues found after the release of Microsoft .NET Framework 3.0. In addition, this release provides security improvements, and prerequisite feature support for Microsoft .NET Framework 3.5. The .NET Framework's Base Class Library provides user interface, data access, database connectivity, cryptography, web application development, numeric algorithms, and network communications. Programmers produce software by combining their own source code with the .NET Framework and other libraries. The .NET Framework is intended to be used by most new applications created for the Windows platform. Microsoft also produces a popular integrated development environment largely for .NET software called Visual Studio.