Cline

We installed Cline in VS Code expecting a simple code completion plugin and instead found ourselves watching an AI agent navigate our entire codebase, read relevant files, write multi-file changes, and submit Git commits — all from a single natural language instruction in the sidebar. The Plan/Act architecture is the key differentiator: Cline first outlines a step-by-step plan for your request, shows it to you for approval, and only then begins making changes. This structured approach caught a potential mistake before it happened during our testing, when the agent initially planned to delete a utility file that other modules depended on.

Being open-source and completely free gives Cline a massive advantage over paid alternatives like Cursor. We connected it to Claude, GPT-4, and DeepSeek through its multi-provider support, and the ability to switch models mid-session depending on the task — Claude for analytical code review, DeepSeek for rapid prototyping — is a workflow flexibility that single-model tools cannot match. The MCP integration also proved valuable, letting Cline interact with external tools and APIs during coding sessions.

The limitation is that Cline runs exclusively inside VS Code, so developers using IntelliJ, Neovim, or other editors are out of luck unless they are willing to switch environments. We also found that on very large monorepos, Cline's initial context loading can be slow, and it occasionally missed files that a human reviewer would have caught. The quality of output is heavily dependent on whichever LLM you connect it to — Cline itself is the orchestration layer, not the intelligence. But as a free, privacy-respecting coding agent that runs entirely locally and puts you in control of the AI provider, Cline has earned its five million installs and then some.