Source : Free On-Line Dictionary of Computing

Z3
     
         The third computer designed and built by {Konrad
        Zuse} and the first computer to successfully run real
        programs.  The computer was ready in 1941, five years before
        {ENIAC}.
     
        Zuse began his work on program-driven calculating machines in
        1935.  His two predessors of the Z3, the Z1 and Z2, were
        unsuccessful mechanical calculating machines.  The Z3 was
        delivered to the Deutsche Versuchsanstalt fur Luftfahrt
        (German Experimental Department of Aeronautics) in Berlin and
        was used for deciphering coded messages.  In 1998, there may
        still be models of Z3 in museums [where?].
     
        The Z3 used about 2600 relays of the kind used in
        telecommunications.  Zuse wrote and implemented the language
        {Plankalkul} on the Z3.  Programs were punched into cinefilm.
     
        Zuse built some more computers after World War II, including
        the Z3's successor, the Z4, which was set up at ETH Zurich,
        Switzerland.
     
        Of the potential rival claimants to the title of first
        programmable computer, {Babbage} (UK, c1840) planned but was
        not able to build a {decimal}, programmable machine.
        {Atanasoff}'s {ABC}, completed in 1942, and Eckert and
        Mauchly's {ENIAC} (US, 1945/46) were special purpose
        calculators, like those of {Pascal} (1640) and {Leibniz}
        (1670).  None of these machines was freely programmable.
        Neither was {Turing} et al.'s {Colossus} (UK, 1943-45).
        {Aiken}'s {MARK I} (1944) was programmable but still decimal,
        without separation of storage and control.
     
        [Features?  Where was it designed?  Contemporaries?]
     
        {(http://www.cs.tu-berlin.de/~zuse)}.
     
        {(http://www.epemag.com/zuse)}.
     
        (2002-07-28)