Cursor

Cursor is a hard fork of VS Code, which allows it to implement AI features at the editor level that standard extensions like GitHub Copilot cannot reach. By utilizing RAG (Retrieval-Augmented Generation) and local file indexing, it provides the LLM with a comprehensive understanding of your project structure, symbols, and dependencies. This enables features like Composer, which can modify multiple files simultaneously while maintaining architectural consistency.

The tool shines in its Agentic Mode, allowing it to execute terminal commands, read documentation on the fly, and iterate on code until tests pass. While it relies on cloud-based LLMs (like Claude 3.5 Sonnet and GPT-4o) for the heavy lifting, the local orchestration layer ensures that the context window is populated with only the most relevant snippets, minimizing hallucinations during complex refactoring tasks.