Citizendium is an English-language wiki-based free encyclopedia project launched by Larry Sanger, who had previously co-founded Wikipedia in 2001.
The project aims to improve on the Wikipedia model by providing increased reliability. It hopes to achieve this by requiring virtually all contributors to use their real names, by strictly moderating the project for unprofessional behavior, by providing what it calls "gentle expert oversight" of everyday contributors, and also through its "approved articles". Approved articles have undergone a form of peer-review by topic experts with credentials, and are closed to real-time editing.
As of 2019, it is mostly inactive.