Source : Free On-Line Dictionary of Computing

Very Large Memory
     
         (VLM) A {processor} and {operating system} that
        can use more than 4GB of {RAM}, which is the limit for systems
        using {32-bit} addresses.
     
        VLM architectures allow {application programs} and {Very Large
        Databases} with more than 4GB of data to be placed entirely in
        {physical memory}, with large performance enhancements.
     
        Some recent processors like the {DEC Alpha} can process 64
        bits of data at a time and use addresses wider than 32 bits.
     
        {Digital Unix (http://www.unix.digital.com/unix/64bit/)}.
     
        (Solaris {http://www.sun.com/solaris/64bit.html}).
     
        (SGI {http://www.sgi.com/Technology/standard/faq.html}).
     
        (Unix 98
        {http://www.UNIX-systems.org/version2/whatsnew/login_64bit.html}).
     
        [How wide are the address busses?]
     
        (1998-07-07)