Figure 1: Microsoft's Embedded OSs Provide Scalability

Kicking the Tires
NT Embedded differs from its desktop relative with its modularized design that uses software components that can be added or removed depending on the requirements. NT Embedded supports all the software applications that can be run on the desktop version and will be so compatible that future embedded versions will be released approximately 90 days after the desktop version. That means applications such as Office, IIS, SQL, Windows Media Player, and DirectX are all offered in NT Embedded. NT Embedded only supports x86 based processors and requires 12MB of memory and 8 MB of persistent storage for a minimal build. NT Embedded has no native real-time support, but third parties, like VenturCom, will provide extensions for soft real-time support. Embedded features, including headless support, read-only boot, solid-state media support for diskless operation, and remote management, are provided for in NT Embedded.

The next version of NT Embedded will be known as Windows XP Embedded (XP Embedded). It will have built-in componentization technology and embedded features like XIP (execute-in-place), compact PCI, a smaller footprint, a better toolkit, and XML, SOAP, and UDDI support. XP Embedded will be fully integrated into Microsoft's .NET strategy for a more network aware OS platform. XP Embedded is expected to ship in the 4th quarter.

Development Tools
Development tools for NT Embedded include: Visual Studio, Target Designer, and Component Designer. Visual Studio is the same development environment used on the desktop version. Software development can be done with Visual C++, Visual Basic, or Visual InterDev, using Win32 APIs, MFC, ActiveX controls, COM, and DCOM.

Target Designer tailors the build process for NT Embedded systems and creates a bootable NT operating system with custom components and applications for an iAppliance or embedded system. It also has a graphical development environment that displays a Windows NT configuration at a component level for developers to customize for their applications.

Figure 2: Target Designer Configures Windows NT Embedded

Component Designer creates custom components that can be added to the Target Designer configuration and provides wizards and a graphical display to create component definition files. These components provide additional enhancements for NT Embedded. The component definition file defines the components that are listed in the Target Designer. The components are imported into the Target Designer so that they can be added to the NT Embedded build process.

Figure 3: Components Designer Builds Components Used in Windows NT Embedded

Server Appliance Kit (SAK)
Microsoft has recently released the Server Appliance Kit (SAK) to speed up development of application specific server appliances such as caching servers, Web servers, and storage servers. Though the initial release of the SAK is based on Windows 2000, future versions will be packaged into NT Embedded's next version, XP Embedded. SAK is a toolkit designed to help developers and OEMs expedite the building of server appliances. SAK supports headless operation and can be managed remotely through Web-based management, SNMP, or Telnet. It is built for high availability systems and contains reliability features like watchdog timers, bios fail-over, automatic mirroring, and appliance monitoring service.

SAK includes:

• Hardware Reference Specifications
  
• Device Driver Kit
  
• Software Components for NAS and Web Server Configurations
  
• Software Development Kit
  
• Documentation
  

Figure 4: SAK Speeds Up the Development of Application Specific Server Appliances

Stiff Competition
NT Embedded will see plenty of competition, especially from the Linux crowd. Linux is somewhat similar in nature to NT Embedded in that it also was born from the desktop environment, has modular software components, and possesses comparable support for security, networking, and Web services. However, Linux's main benefit to most of its users (other than the fact its not Microsoft) is its open source model with low cost for development and no licensing fees, though this is changing for some Linux platforms. Linux, with its large development community, provides quite a challenge for NT Embedded in the high-end iAppliance arena.

Bottom Line
Due to the pressure from Linux, Microsoft is slightly modifying the way it licenses to developers and OEMs. It has created the Windows Embedded Startup Program (WESP) to encourage new companies to use Microsoft's embedded platforms. WESP provides access to grants for free tools and run-time licenses for qualified companies.

For most companies building and selling devices, using Windows NT Embedded 4.0 requires two separate steps:

• A copy of Windows NT Embedded 4.0, which contains Target Designer, is required to create a customized Windows NT Embedded 4.0 image.
  
• A runtime operating system license is required to sell devices that use the customized Windows NT Embedded 4.0 image that is created by Target Designer.
  

Windows NT Embedded 4.0 with Target Designer and runtime licenses can be obtained from Microsoft's distributors, who include:

• Avnet Applied Computing
  
• Arrow Electronics
  
• Annasoft Systems
  
• BSquare Corp.
  
• VenturCom, Inc.
  

NT Embedded was Microsoft's initial foray into delivering a more feature rich OS for iAppliances. It lacked certain features required for high availability server systems, but it provided Microsoft with a lesson on what was needed for future versions. It appears XP Embedded will capitalize on some of this knowledge. The SAK is also a step in the right direction for providing a more turnkey environment for bringing iAppliances to market faster.