Overview GitHub Copilot is the AI pair programmer that invented this category. Built by GitHub with OpenAI's underlying models, it shipped a technical preview in June 2021, went general availability in 2022, and by 2026 is the default AI coding tool on roughly 90% of Fortune 500 developer laptops. Every serious competitor — Cursor, Claude Code, Windsurf, Codeium — is defined in part by how they compare against Copilot. The one line positioning: GitHub Copilot is the AI coding tool your organization can actually deploy. It runs in every editor developers care about — VS Code, JetBrains, Neovim, Xcode, Visual Studio, Eclipse. Your admin can control which models are allowed, which repos are indexed, whether prompts are retained. Your compliance team can point at Microsoft's SOC 2 report and move on. This sounds bureaucratic. It is. It's also the exact reason Copilot dominates the enterprise seat count while Cursor dominates the solo dev conversation. In 2026 Copilot has matured well past its original "ghost text as you type" scope. Copilot Chat handles multi file edits inside your IDE. Copilot Coding Agent takes GitHub issues to PRs autonomously. Copilot Workspace — Microsoft's answer to Cursor's Composer — is rolling out broadly. Model choice is generous: Claude Sonnet 4.5, GPT 5, and Gemini 2.5 Pro are all rotatable per query on Pro+ and Business tiers. What was once a single autocomplete engine is now a full agent suite living underneath the same GitHub subscription. Copilot's audience is unambiguous: developers inside companies where…