Versionize makes it easier to go from an initial hunch to a mature idea. It is a structured and flexible replacement for the personal notebook - a place for people to capture ideas and then continuously improve and revise them by adding text, images and links. Versionize is also a collaborative tool. Ideas can be made public for anyone else to participate in the improvement process. Versionize is built on and inspired by the version control system Git, which provides a wide range of features uncommon in existing ideation tools and is used extensively in some of the most successful collaborative projects in the world.