CROSS-PLATFORM (CONT...)

The term "cross-platform" can also apply to hardware options such a computers that will run under more than one operating system. However, this is not technically crossing a platform since it is merely equivalent to having two independent computers in one housing. Some, but not all, lessons authored in DOS and Windows may run on a Mac or PowerPC computer, but those that do may run painfully slow due to being run in emulation rather than direct form. Conversion software is available for converting Mac HyperCard Stacks into Multimedia ToolBook Windows books. Although this software works well for simple books (e.g., books having no complex animations and high-resolution graphics) that aren't in color, it doesn't work well for complex books with greater color depth, high resolution graphics, or complex animations. The same problem arises in most conversion software (e.g., that of Macromedia's Authorware and Director). Even ToolBooks created in 24 bit color PCs may not be suited for PC displays having lower color depths. Mac computers attempt to dither 24 bit color images into acceptable images for lower color-depth Mac computers, but PCs do not dither these images automatically. As books become more complex, a point is reached where authors must rewrite books for Mac and Windows operating systems. The Internet changed much of the worries about cross-platform capability. Increasingly, authoring software and other types of software are gearing up for playback on the World Wide Web (WWW) such as the Shockwave reader for Macromedia's Director and Authorware and the Neuron reader for the Asymetrix ToolBook products. (See also ActiveX Authoring , CORBA , Native , Operating system , PDA , and CGM )