Spark is a project to improve the authoring experience for Drupal content creators. It aims to develop features like inline editing, customizable page layouts, dashboards and workflows, mobile authoring, and more. The project is led by Dries Buytaert and others from the Drupal community. They have outlined a roadmap and are actively working on components like content editing and page layouts, with the goal of integrating successful features into Drupal 8.