Quercus Programming languages for the Java Virtual Machine JVM and Javascript Posted on 9. November 2009 by Robert Tolksdorf9. November 2009 Quercus is Caucho Technology’s fast, open-source, 100% Java implementation of the PHP language (requires JDK 1.5). URL: http://www.caucho.com/resin-3.0/quercus/index.xtp