Willows Toolkit

                                  Overview

     ENABLING YOUR MICROSOFT® WINDOWS® APPLICATIONS TO RUN ON UNIX® AND
                                 MACINTOSH®

The Cross-Platform Challenge

Developing applications which can run on multiple platforms, such as
Microsoft Windows, UNIX or Macintosh systems, poses a real challenge to the
software development community today. Your customers expect to have the
applications you develop to be made available on many platforms, matching
their heterogeneous hardware infrastructure. They also expect to have
versions of your software introduced on all operating systems
simultaneously.

Your challenge is to develop and simultaneously introduce high quality
applications on all popular platforms, typically with no incremental
staffing. You want to develop to a single source tree for ease of
development, testing and maintenance, and you don't want to get locked into
proprietary environments or APIs which reduce the talent pool you can staff
from, and which force you to depend on a single vendor for support and
future platform introductions.

Your solution is to develop to the de facto industry standard: the Windows
API. This environment provides not only the broadest selection of
development tools, it also caters directly to the largest segment of
potential customers for your products. But how do you get from there to
other environments, such as UNIX, Macintosh or even yet-to-be-developed
systems? You use The Willows Toolkit for UNIX and Macintosh and embedded
systems.

The Willows Solution

Willows Software offers the Willows Toolkit for migrating Windows
applications to alternative platforms. The Willows Toolkit consists of the
Willows Twin Libraries and Tools necessary to port Windows applications to
platforms other than the traditional Windows-based PC. The Willows Twin
Libraries are released in source form over the internet with the GNU Library
Public License. The Willows Toolkit supports a wide range of platforms,
including several varieties of UNIX, the Macintosh and several embedded
systems as well.

The software libraries (TWIN32 and TWIN16) are virtually identical for all
supported platforms enabling developers to maintain a single source tree.
All platform specific code has been isolated in a small library, written
specifically for each new platform. This platform specific library is called
the Platform Abstraction Layer, and represents a small fraction of the
Willows Twin Libraries code base, yet allows the software on each platform
to take full advantage of specific functionality and native performance. The
Willows Toolkit includes all the tools to port sources, resource compilers
that allow you to include menus, bitmaps and icons in an application and a
module definition compiler for building shared libraries.

Architecture

The Willows Toolkit is made up of :

   * TWIN32 & TWIN16 Libraries
   * TWIN Platform Abstraction Layer

The Windows-compatible application interacts with the Willows TWIN Library
the same way that the application works in a Windows environment: calling
API functions, receiving messages, loading resources and even launching
other Windows applications and DLLs.

The TWIN Library interacts with the Willows Platform Abstraction Layer,
making requests for graphical, window, or system operations and receiving
responses or asynchronous messages.

Binary Emulation

To verify the implementation of the Willows TWIN API's, a Windows 3.x
compatible binary loader has been written, that allows the Willows TWIN
libraries to execute existing executables, dll's and drivers. The loader is
a stand-alone Willows Application that has been linked to the Willows TWIN
libraries, and routes calls from an existing application to the Windows 3.x
API's to the corresponding Willows TWIN API. This application loader can
successfully load and execute a wide range of existing applications, but for
commercial application support, you should consider WABI from Sun, which is
available on linux from Caldera. This link is an example screenshot of the
Willows Twin Binary Emulator running a well known windows application
running on Linux with the FVWM95 Window Manager.

Supported Features

Windows APIs (16- and 32-bit)

MDI (Multiple Document Interface)

Windows 3.x Common Dialogs

   * Animation
   * Choose Color
   * Choose Font
   * Find
   * Replace
   * Print
   * Open File
   * Save File

Windows 32 Custom Controls

   * Drag List
   * Header Controls
   * Image List
   * List View
   * Progress Bar
   * Property Sheet
   * Status Windows
   * Tab Controls
   * Tool Bars
   * Tooltips Controls
   * Trackbars
   * Treeview Controls
   * Up-Down Controls

Communication

   * WinSock
   * WNET
   * DDEML
   * Serial Driver

Diagnostic Tools

   * API Profiling
   * Symbolic Debugger
   * Binary Emulation

Clipboard Operations, Metafiles. Registration Database

Support for .ini, .hlp, and .rc Files

MFC 4 Support

Development Tools

   * Resource Compiler
   * TwinHelp Help File Viewer
   * Graphical Configuration Tool

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Copyright © The Canopy Group. All rights reserved.
Revised: Jul 19, 1997