Cline

Cline is an open-source, autonomous coding agent that runs inside a developer's editor rather than as a separate chat window. It can read and edit files across a whole project, run terminal commands, and use a browser, working through multi-step tasks with a 'Plan then Act' mode that lets a developer review its strategy before it touches any code. It's aimed at professional developers and engineering teams, including reported users at companies like Samsung, Salesforce, Oracle, Amazon, and Microsoft. Teams can encode their own standards in .clinerules files so the agent follows project conventions, and larger setups can delegate work across multi-agent teams with scheduled runs. It connects to Claude, GPT, Gemini, AWS Bedrock, Azure, Ollama, DeepSeek, and other OpenAI-compatible models, supports Model Context Protocol servers, and integrates with Slack, Linear, and Discord. It ships as a VS Code extension, with JetBrains support in early access, and also runs in Cursor and Windsurf. The extension itself is free and open source (Apache 2.0), but there's an honest cost tradeoff: it doesn't bundle model access, so users must supply their own API keys and pay their chosen LLM provider directly.