Code‑first guide to top .NET LLM open‑source projects in 2025: Extensions.AI, Semantic Kernel, LLamaSharp, ONNX Runtime, Whisper and vector DBs.
Top .NET AI/LLM Open‑Source Projects in 2025
Category: Artificial Intelligence
Multi‑Agent Orchestration & A2A Workflows in Semantic Kernel
Build secure multi‑agent systems with Semantic Kernel in .NET: A2A handshake, orchestration patterns, and a research‑to‑summary pipeline.
Vector Stores & Memory in Semantic Kernel for .NET
Build long‑term memory in .NET with Semantic Kernel. Compare Azure AI Search, Pinecone, pgvector, and ship reliable RAG.
ChatGPT API in C#: The Complete Working Guide
Integrate ChatGPT into .NET like a pro: streaming, tools, JSON output, resilience, and tests. Copy‑paste C# you can ship today.
Semantic Kernel: One Client for OpenAI, Azure & Local LLMs
Switch between OpenAI, Azure AI & local LLMs with one code path. Learn setup, streaming, tools, and embeddings in .NET with Semantic Kernel.
Semantic Kernel 2025: Build C# Intelligent Agents Fast
Learn how to master the new IAgent interface in Semantic Kernel 2025 to create self‑planning, self‑healing intelligent agents with .NET.