GitHub Copilot X is an advanced version of the AI pair programmer that provides a seamless experience for developers. The tool is equipped with chat and terminal interfaces, supports pull requests, and has adopted OpenAI's GPT-4 early on. With the AI's context-aware conversation feature, developers can seek help in solving problems, fixing errors, and generating unit tests. The documentation feature provides personalized answers with inline citations, allowing developers to spend less time searching for information. GitHub Copilot X also automates PR descriptions, eliminating the need to fill out templates manually, and can automate automated testing by pointing out missing unit tests and generating new test cases after every build. Overall, GitHub Copilot X envisions the future of AI-powered software development by integrating AI into every aspect of the workflow.