In this episode of the Syntax podcast, Cassidy Williams and Harald Kirschner explore the exciting new features of GitHub Copilot unveiled at GitHub Universe. They highlight a live demo that showcases multi-file editing and the innovative Copilot custom instructions, which allow developers to tailor Copilot's behavior through a markdown file. The conversation also addresses the challenges of conducting live AI demonstrations and emphasizes the need for intuitive UI/UX design in AI tools. They discuss ongoing efforts to experiment with various interfaces to improve user experience and productivity. Additionally, they touch on Copilot extensions that empower developers to create custom agents within the Copilot chat, as well as the expansion of Copilot's capabilities to Xcode.