Semantic Kernel

Microsoft's open-source SDK for integrating LLMs into .NET (and Python/Java) applications. Semantic Kernel provides abstractions for prompt management, tool/function calling, memory (including vector store integration), and AI orchestration. It's the closest thing the .NET ecosystem has to LangChain, though comparing them is a bit like comparing a Swiss Army knife to a different Swiss Army knife. They both have blades and corkscrews, but the engineering philosophy and the things that are sharp are in different places.

Why it matters for writers: Semantic Kernel is the most mature framework for building AI-powered applications in C#. If you're documenting a .NET AI project or evaluating orchestration options, it's typically the first framework to consider. Lexichord's orchestration layer uses a custom architecture rather than Semantic Kernel, largely because technical writing workflows have requirements (style guide enforcement, terminology databases, document-type-specific behavior) that don't map cleanly to Semantic Kernel's abstractions. Sometimes the Swiss Army knife needs a blade it doesn't have, and you make your own.

Related terms: Orchestration · ML.NET · NuGet