AG2 continues AutoGen's ConversableAgent model: agents collaborate through messages, while GroupChatManager selects the next speaker by round robin, manual choice, randomness, or an LLM.
Microsoft merged Semantic Kernel and its own AutoGen into Microsoft Agent Framework, which hit 1.0 GA on 2026-04-02 for .NET and Python (Go is still public preview). The absorbed autogen-agentchat has not shipped since 2025-09-30. But AG2, the fork on the original authors' side, never merged — it shipped 1.0.2 six days ago, and `pip install autogen` gets you AG2, not Microsoft. This post covers MAF's abstractions, the migration clock, and how to read the tangle of names.