James Werner “Jamie” Zawinski (born November 3, 1968 in Pittsburgh, Pennsylvania), commonly known as jwz, is an American formerly professional Software Engineer responsible for significant contributions to the free software projects Mozilla and XEmacs, and early versions of the Netscape Navigator web browser. He maintains the XScreenSaver project which provides screenblanking for Mac OS X and for Unix and Unix-like computer operating systems using the X Window System. Zawinski is currently the proprietor of the DNA Lounge, a nightclub in San Francisco.