Constitute: The World's Constitutions to Read, Search and Compare
From the Website:
The Comparative Constitutions Project (CCP) is directed by Zachary Elkins (University of Texas, Department of Government), Tom Ginsburg (University of Chicago, Law School), and James Melton (University College London). The project was seeded by grants from the National Science Foundation (SES 0648288) and the Cline Center for Democracy at the University of Illinois.
The intent of the project is to investigate the sources and consequences of constitutional choices. Towards this end, the investigators collect, analyze, and data on the formal characteristics of written constitutions, both current and historical, for most independent states since 1789.
In September 2013, the CCP launched Constitute with Google Ideas. The site provides an indexed repository of Constitutional text for every Constitution currently in force.