Compare AI tools

	Aider A	Lex A	GitHub Copilot B	Windsurf A
Tagline	Terminal-based AI pair programmer. Git-aware, model-flexible.	Google Docs with an AI collaborator baked in.	Microsoft/GitHub's autocomplete. Deep VS Code + JetBrains integration.	Codeium's agentic IDE. Cascade agent + strong free tier.
Category	coding	writing	coding	coding
Pricing	Free (open source) + whatever API you use	Free + $12/mo	Free (limited) + $10/mo Pro + $19/mo Business	Free + $15/mo Pro
Best for	Developers who want open-source tooling with full control.	Essays, long-form drafts, thinking on the page.	Teams with GitHub already. Devs who don't want to change IDEs.	Developers who want Cursor-like power for less money.
Strengths	Works in any terminal Auto-commits changes with meaningful messages Works with any model (Claude, GPT, local) Minimal learning curve	Clean writing UX — distraction-free +++ prompt triggers AI help Collaboration + AI feedback together	Great enterprise story Works in your existing IDE Chat + autocomplete	Cheaper than Cursor Cascade agent for multi-file tasks Solid free tier
Weaknesses	Terminal-only Less agentic than Claude Code Setup on Windows is fiddly	Less feature-rich than Google Docs AI ceiling below dedicated tools	Less agentic than Cursor/Claude Code Model quality varies	Smaller community Model selection more limited
Kai's verdict	A-tier. The right answer if you want open-source + terminal-native + model-agnostic.	A-tier. Beautiful UX. The writing app I'd pick if I only wrote long-form.	B-tier. Solid for autocomplete but the category moved past it. Pick Cursor unless you can't.	A-tier. Close second to Cursor. If $5/mo matters, start here.
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