The Commonwealth Legal Information Institute (CommonLII – www.commonlii.org – pronounced ‘Common-lee’), is a non-profit and free access website for legal information from all countries that are members of the Commonwealth and their territories (more than 60). CommonLII also covers a small number of significant non-Commonwealth countries and territories that have a legal system based on the common law. The main purpose of CommonLII is to provide a comparative law facility by which the laws of all common law countries can be searched and compared. In relation to case law, CommonLII assists in making the ideal of an international common law a reality, by providing the case law collection with the broadest geographical scope, and the only free access international citator (LawCite). In relation to legislation, CommonLII makes it easier to compare legislative developments in the same subject-areas across Commonwealth countries, and can therefore assist in the process of law reform, as well as increasing the transparency of each country’s legal system. CommonLII also makes it easier to find commentaries on the law from Commonwealth and common law countries, including law reform reports and some law journals. This paper explains CommonLII’s development since its launch in 2005 (its partners, scope and supporters; the range of content from each country; and technical features, illustrated by searches), emphasising the significance of the addition of the English Reports 1220-1873 and the LawCite international citator. It concludes with an outline of likely future developments due to funding provided for 2010-11 by the Australian Research Council, Commonwealth Secretariat and Australian Attorney-General’s Department.