If you've been watching the open-source LLM space, you've probably noticed it's been a great couple of years. Llama, Mistral, Phi, Qwen — a whole zoo of models you can download and run on your own machine. Google's entry into that zoo is Gemma , and the fourth generation, Gemma 4 (released April 2, 2026), is the biggest leap yet: built from Gemini 3 research, multimodal (text + image + video + audio), 256K context, native function calling, configurable "thinking mode," and — finally — a clean Apache 2.0 license . In this post we're going to: Understand what Gemma 4 actually is, with an architecture diagram Get it running on your laptop with Ollama in about 5 minutes Chat with it from the terminal Send it an image and ask questions about it Turn on thinking mode for harder problems Call it from a Python script like a real API Build a small project that glues it all together No GPU rental, no API keys, no telemetry. Let's go. Heads up: This guide assumes zero ML background.…