LangChain — LangChain is the framework that powers most production LLM apps you've used. It's the plumbing behind the magic. What it provides: - Chains: Connect LLM calls with logic - Agents: LLMs that decide what actions to take - RAG: Retrieval-augmented generation made easy - Memory: Persistent context across conversations If you're building anything serious with LLMs, you'll probably touch LangChain. Python and JS/TS support. Huge ecosystem.

v0 by Vercel — v0 generates React components from natural language. Describe a UI, get production-ready code with shadcn/ui and Tailwind. What makes it special: - Outputs clean, copy-paste-ready code - Uses shadcn/ui components (no proprietary stuff) - Iterates through conversation - Free tier for experimentation Built by Vercel, so the quality bar is high. Best for UI components rather than full apps. Surprisingly good at matching designs.