task, hence the market for PIGUI packages. User interface approaches Most, if not all, PIGUI packages take one of three approaches to providing platform independence. The two most common approaches are the `layered' and the `emulated' user interface but an up-and-coming approach is `API emulated' interface. Packages using a layered interface access native, third party, GUI-building toolkits to provide the look-and-feel compliance for each particular GUI. Layered user interfaces have the advantage that, since they depend on other products which concentrate on a single GUI, they have to provide less software (and, hence, are usually less expensive) than emulated interfaces. Layered interfaces are also more likely to get the native look-and-feel correct on all platforms. In an emulated user interface, the PIGUI's resultant code produces low-level calls and all the look-and-feel compliance is handled by the PIGUI software itself (e.g., for OpenWindows support, the software would NOT produce an XView program that must be compiled with the XView toolkit; the software would produce code that interfaces directly with X intrinsics). To provide an emulated user interface, a package provider has to develop a lot of extra code for look-and-feel support. Emulated user interfaces have the advantage that someone on a X11 workstation, for example, can see how the Macintosh-style UI will look (since the look-and-feel is part of the product). Emulated interfaces have the opportunity to provide a faster GUI than does a layered interface; in addition, it does not require purchase of (or learn how to use) other packages to build GUI software. A third approach to platform independence is emulating one of the supported target's APIs (usually, the Microsoft Windows API) to target other GUIs. With one of these products, one would program using the emulated API and the code would be (to the extent to which the product provides portability) portable to other GUIs. Features PIGUI packages are pretty similar in their basic functionality; they each provide subroutines or objects that allow the user to build windows, buttons (regular as well as radio buttons and check boxes), menus, and the like. Some areas of differentiation are: support for the platforms needed, the choice of implementation language, availability of source code, support for printers and other devices, support for various character encoding schemes including Unicode, capability to support draw-package-like features, bitmap (and icon) support, the approach to platform independence, nifty high-level widgets, and price (complete price including royalties