GitHub Copilot uses OpenAI Codex to suggest code and entire functions in real-time right from your editor. Trained on billions of lines of public code, GitHub Copilot turns natural language prompts including comments and method names into coding suggestions across dozens of languages.

Copilot.vim is a Vim/Neovim plugin for GitHub Copilot.

Source: github/copilot.vim: Neovim plugin for GitHub Copilot

Official and written by tpope. I had thought that Neovim was required for Copilot, but apparently that was never the case or is now no longer the case.