Microsoft Visual Studio is available in multiple versions and editions. To use the .NET API for AutoCAD 2011, you need to use:

• Microsoft Visual Studio 2008 with Service Pack 1
• Microsoft .NET Framework 3.5 with Service Pack 1

If you are using AutoCAD 2007 through AutoCAD 2009, you should use:

• Microsoft Visual Studio 2005
• Microsoft .NET Framework 2.0 or later

Microsoft Visual Studio is offered in two editions: for free and for pay. The free edition is known as Microsoft Visual Studio 2008 Express Edition, while the for pay editions vary by name and price due to the different development tools that are incorporated into them. Microsoft Visual Studio 2008 Standard Edition is the entry level edition which provides improved debugging over Microsoft Visual Studio 2008 Express Edition along with a number of other features. The most common edition of Microsoft Visual Studio used by developers is Microsoft Visual Studio 2008 Professional Edition.

There are four main advantages to using Microsoft Visual Studio:

• Robust and accessible development environment that has a modest learning curve.
• VBA and VB.NET syntax are similar, which makes it an ideal environment for existing VBA users.
• Visually intuitive and extensive dialog box creation tools.
• Projects can be built as a standalone executable or DLL assembly which can then be loaded into AutoCAD for execution.

For more information on the different editions of Microsoft Visual Studio, see http://www.microsoft.com/vstudio and http://www.microsoft.com/express.