GitHub is launching a new Git-backed wiki system to enhance user experience by addressing feedback on the current system, featuring improved support for multiple markup formats, including Markdown, and leveraging Git for history and change comparisons. This new system allows for easy referencing of images, importing and exporting wikis as Git repositories, and enables local content viewing and modification through the Gollum ruby library. The platform aims to improve user interactions by sanitizing javascript and CSS, ensuring users remain logged in when viewing open-source wikis. While still in beta, users are encouraged to upgrade their wikis, with the company planning to disable classic wikis by September 12th.