The selection of VB.NET and C# over other .NET languages (such as F# or managed C++) is a strategic decision driven by Microsoft’s target audience. VB.NET was chosen to provide a migration path for millions of existing VBA developers. For them, the syntax remains familiar—event handlers, Dim statements, and Sub / Function blocks—while the underlying object model shifts from COM-based to .NET-based. This lowers the cognitive barrier for legacy Office and AutoCAD customizers transitioning to more modern platforms. Conversely, C# inclusion targets professional software engineers who require fine-grained control, type safety, and advanced features like lambda expressions, LINQ (Language Integrated Query), and asynchronous programming ( async/await ). By offering these two languages, VSTA 2015 serves two distinct user personas: the power-user-turned-customizer and the seasoned developer.
However, the language support in VSTA 2015 is notable for what it excludes. It does not natively support dynamic scripting languages like IronPython or IronRuby, nor does it offer a full REPL (Read-Eval-Print Loop) environment akin to more modern scripting hosts. This limitation is intentional. VSTA is not a general-purpose scripting sandbox; it is an integrated development environment (IDE) embedded within a host application (e.g., Dynamics AX, SolidWorks, or various industrial control systems). The host’s object model is exposed to both VB.NET and C# through a consistent set of primary interop assemblies. By restricting language support to two statically-typed (albeit with dynamic capabilities in C#) languages, VSTA ensures that the host application’s API contract is unambiguous. Type resolution, IntelliSense, and compile-time checking work predictably across all customizations, reducing runtime errors that could destabilize the host. The selection of VB
In conclusion, the language support in Microsoft Visual Studio Tools for Applications 2015 is a masterclass in focused pragmatism. By supporting only VB.NET and C#, Microsoft deliberately sacrificed polyglot diversity in favor of clarity, backward compatibility, and runtime robustness. VB.NET serves the vast installed base of VBA customizers, while C# attracts professional developers seeking modern language features. Together, they leverage the full power of the .NET Framework 4.6, ensuring that host applications can be extended reliably. For organizations deploying VSTA 2015, the message is clear: automation is best achieved not through a proliferation of languages, but through the disciplined use of two complementary, powerful, and well-supported dialects of the .NET ecosystem. This lowers the cognitive barrier for legacy Office