VSTA is a .NET-based application customization technology designed to be embedded into applications to enable developers to create custom experiences on top of those applications.

Over the past nine years, Microsoft has successfully supported packaged software vendors, tools vendors and systems integrators who need to extend and customize their applications to better meet end-user needs at reduced cost and effort. VSTA will continue Microsoft’s leadership in development tools started by Visual Basic for Applications (VBA), first shipped with Microsoft products in 1993 and made available to other software vendors in 1996. VSTA delivers a significantly enhanced customization environment that takes advantage of technology introduced with the .NET Framework to provide the next generation of application customization technology. We understand that moving applications and users to a new platform is difficult. To ease this transition we have designed VSTA to operate side by side with VBA in the same host application.