WORKSHOPS

Alternatives For Cross-Platform Applications

You could sidestep the entire problem by standardizing on a single platform. In some organizations, it might be easier to write your own applications instead of taking away nonsupported platforms and operating systems. Of course, placing Windows machines on everyone's desktop for the sole purpose of running one or two applications simply isn't cost-justifiable. But don't lose hope. There are other options when it comes to serving Windows applications to other desktop platforms.

We tested a few of these solutions in our Madison, Wis., lab and found that each has pluses and minuses, but all are good solutions if used appropriately. Each technology has its place within the enterprise, but if y ou are looking for complete binary compatibility (including DOS applications), you will need emulation or Windows NT application servers. If you simply require access to Windo ws applications on Solaris machines, the Windows Application Binary Interface (WABI) bundled with Sun Microsystems' Solaris works just fine.

Technology Options The most obvious method of serving Windows-based application on non-Windows platforms is via emulation. SoftWindows from Insignia Solutions fits this bill nicely. SoftWindows will get you complete binary compatibility with every Windows application (including Win95) on the Power Macintosh and a variety of Unix platforms, including those from Digital Equipment Corp., Hewlett-Packard Co., IBM Corp., Silicon Graphics and Sun. In addition, SoftWindows supports almost all PC networking clients, including Novell NetWare, TCP/IP and LAN Manager for DOS.

If you've got only a few key applications, the easiest solution to roll out en masse that also offers complete binary compatibility is a Windows NT application server-based solution. This runs the application on the server, passing the keyboard, mouse and display I/O to the client system--much l ike X terminals or X servers that connect to X clients.

You can think of this as Windows NT with multiple display heads. Products offering this type of solution include Citrix Systems' WinFrame and Insignia Solutions' NTRIGUE. In addition, these solutions can be accessed over the native X protocol or the very lightweight Intelligent Console Architecture (ICA) protocol.

For specific markets there are functional call translation-based offerings such as SunSoft's WABI. Instead of emulating the Intel Corp. chip and running Windows in emulation, WABI maps the Windows functions directly to Xlib calls. Although quite fast, it's not compatible with all Windows applications--and you can forget about DOS. To its credit, WABI supports the majority of applications used, including Microsoft Office and Lotus Development Corp.'s SmartSuite applicatio ns.

Emulation The first solution to the Windows application access problem seemed very intuitive at the time--emulate the Intel chip. Although early versions were slow, current chip speeds make this option quite tolerable. Emulation offers complete binary compatibility, even with DOS applications. It also makes better use of local resources, including the CPU, floppies and other local devices. In addition, installing a local copy of SoftWindows on Unix workstations and Apple Computer Macintosh machines is less expensive than the same number of concurrent licenses for NTRIGUE.

Unlike the application server scenario, emulation runs applications locally. This is of great use to those who need full binary compatibility while tied to a network connection. However, it would be very expensive to dial into an NTRIGUE server simply to run a Windows application using your Macintosh PowerBook. In addition, Insignia NTRIGUE Net Client has limited support for the local machine's hardware, such as floppies, sound cards and CDs.

Currently, DOS 6.22 and Windows 3.1x emulation is provided by SoftWindows 3.0 (SoftWindows 95 bundles Windows95), which is available for the Power Macintosh; SoftWindows 2.0 is available for a variety of Unix platforms. We've been living with Insignia's Power Mac version for a few years and have found it to be quite reliable and stable. Installation is simple and configuration includes everything you would expect to find on a Wintel machine, including support for TCP/IP, NetWare and NetBIOS protocols.

We did find a few anomalies in SoftWindows for the Power Mac with regard to networking. Because NetWare and TCP/IP protocols exist on the Macintosh (SoftWindows is an application that sits atop the Macintosh OS), you need to make a decision on access to those protocols. When operating in the SoftWindows environment, networking sits on top of MacIPX and MacTCP (or Open Transport TCP/IP) or you can run native protocols within the emulation. By riding on top of the existing protocols stacks, networking is given access to both the MacOS and Windows environments. However, some of the network speed in the Windows environment is lost. You will have to choose between speed and access.

Although emulation puts processing power on the desktop, don't forget that you have lost the centralized application management that a Citrix or NTRIGUE solution provides. If you're concerned about application security or are a proponent of central management, this solution only adds to your management burden.