Duplication Detector is a tool created for Wikipedia:Copyright problems on the English Wikipedia. It compares any two web pages to identify text which has been copied from one to the other. Either, neither, or both pages may be current or old revisions of a Wikipedia article. For more information, see:
Originally created by dcoetzee the PHP source for Duplication Detector is available under the Simplified (2-clause) BSD License. It does not require wmflabs to run, so feel free to download and use it yourself using your own webserver or the php command-line tool.