I thought that the following explanation offered by an Apple Java engineer, Gerard Ziemski, might be of general interest to this newsgroup. The indented text is a full quote of his message to the Java-Dev list.

        Date: Tue, 26 Feb 2002 15:30:30 -0800
        Subject: hwaccel notes

        hi guys,
        
        Here are few notes I wrote in response to your questions about hwaccel.
        
        
        Q: What does com.apple.hwaccel do?
        
        A: You can use it to turn hwaccel off for all machines, by
        setting it to false. If the option is set to true, which is the
        default, you still have to explicitly define which
        configurations you want to support, see com.apple.hwaccellist.
        Note: there is currently no mechanism that would let you turn
        hwaccel on for all configurations.
        
        
        Q: Why did we decide to use com.apple.hwaccellist?
        
        A: The hwaccel mechanism is implemented on top of OpenGL. There
        are OpenGL bugs that are specific to only certain
        configurations. We needed a mechanism that would let us control,
        on per video graphics card, whether to turn hwaccel on or off.
        
        If you look in ~JavaVM.framework/Versions/1.3.1/Home/lib you
        will notice a glconfigurationlist.properties file. In there, we
        list all the configurations for which we think hwaccel can be
        turned on. Right now the list doesn't contain any active
        configurations, the file actually has some of them listed, but
        they all are commented out. However, in the future, when we
        decide to turn hwaccel on by default, this will be the list
        containing the "blessed" configurations. You, as the developer,
        will be responsible for deciding if you want to support more
        configuration than listed by us in that file.
        
        The final list of supported configuations is the union of those
        listed in glconfigurationlist.properties file and those listed
        by you using the com.apple.hwaccellist property. Note: there is
        currently no mechanism that would let you turn hwaccel off for
        any of those configurations that are listed in
        glconfigurationlist.properties.
        
        
        Q: What is hwaccel_info_tool?
        
        A: hwaccel_info_tool is a small command line tool that you can
        use to find out the name of your configuration for the purposes
        of adding it to the hwaccellist.
        
        
        Q: Which Macs support hwaccel?
        
        A: The very first requirement is that the OpenGL must be
        supported. Second, at this point of time it is safe to say that
        all the macs with at least 16Meg of vram are supported. The macs
        with only 8Meg of vram, will work fine in thousands of colors
        mode. If you turn on millions of colors, you will quickly run
        out of vram and depending on the size of a window, we will have
        to turn it off if the size becomes too big.
        
        You should be free to experiment with hwaccel and any new video
        graphics cards. In our code we have extensive error checking
        mechanism, which employed with some heuristic in our code,
        determines when we can use hwaccel. If for some reason we
        determine that we can't use hwaccel, we will just turn it off on
        the fly.
        
        
        Q: How do I tell whether hwaccel is on or off?
        
        A: The easiest way to tell whether hwaccel is on or off is by
        noticing if the grow box of the window is drawn or not. If the
        hwaccel is off the grwbox will be visible. If the hwaccel is on
        the growbox will not be visible. A good example of when bugs
        become a feature ;-)
        
        
        Someone suggested that we come up with a Java section in "System
        Preferences" for controlling Java apps that would include such
        things as hwaccel, swing options, hotspot memory heap size etc.
        I personally think this is a terrific idea, which, in fact we
        thought of doing some time ago. Please remember that you can
        file bugs if you want to see new features or some aspects of our
        implementation mechanism changed.
        
        Please play around with hwaccel and file any bugs you will run into.
        
        cheers