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Middleware: Over the OS, Under the Apps

Middleware: A term so stretched with multiple meanings, it's as shapeless as a wet sock. Let's start with the word itself.

"Middle" means between. "Ware" is a shortcut to "software." In the case of advanced digital set-tops, middleware is software that sits between the operating system, and the interactive applications above it.

Middleware is a bridge. It connects the hardware and its operating system to the ITV goodies. It wasn't needed in early digital boxes, because those boxes did a limited number of things. They took a digital signal in, translated it back to analog, and sent it to the TV. They tuned channels. The most interactive thing was the electronic-program guide.

To add chat, e-mail, clickable ads, and the rest of ITV's harvest, the boxes need more stuff. They still need an operating system, to tell the chips what to do: Tune this channel. Descramble that one. Get the guide. To do more than that, and in a non-proprietary way, they need that middleware bridge to the apps.

The term entered the cable lexicon around 1997. Remember when Cable Television Laboratories Inc. escorted cable's top CEOs around Seattle and the Silicon Valley? That trip, organized to ascertain the Internet's impact on set-tops, ultimately lightened Microsoft Corp. by $6 billion: $1 billion to Comcast Corp., $5 billion to AT & T Broadband a few years later. (And those are just the domestic investments.)

Yet Microsoft's zeal in those ground-zero days of set-top software is what prompted cable to start pondering control. It didn't hurt that Navio, now Liberate Technologies (and Network Computer Inc., in between), was also on the scene, pitching a "middleware" alternative to Microsoft's operating system.

From the beginning, cable wanted middleware for two reasons: Portability, and control. Portability was needed to assuage the FCC's mandate for retail set-tops. Those are set-tops you can buy at a store, no matter who makes them, what their operating system is, or who scrambles premium channels.

Middleware control ensures that ITV apps writers go to cable for distribution, and not an outside software company-like whoever produced the operating system. Plus, middleware is intrinsically based on open standards, theoretically speeding deployment and shunting proprietary locks.

Here's why control is an issue. With or without middleware, applications providers-the makers of games, e-mail, chat and clickable ads-need to know how to write software that runs on various set-tops, with various operating systems. They need to know how fast the processor is, how much memory is available and how to place items on the TV screen.

They write applications using a specific set of guidelines, called "APIs" (application program interfaces). Without middleware, the operating system supplier controls the APIs.

Think of the operating system you use now, on your PC. Probably Windows. Think of what you do the most. Probably Word, Excel, Access. While scores of software writers can access Windows APIs, Microsoft had first crack at them. Because they make Windows, they knew best how to write applications for it.

As one MSO engineer said to me years ago: "If one software company were to provide the operating system and the interactive APIs, I'd be left with one piece of control: the keys to the headend."

CableLabs stemmed this concern by placing middleware at the heart of its OpenCable specification. Last month, to side-step the confusion around the word "middleware," it renamed that effort "OpenCable Application Platform."

CableLabs also split the project into two layers: the execution environment, in which interactive applications actually run, which will be written by Sun; and the presentation environment, which stipulates where and how interactive icons are placed on the TV screen. Microsoft and Liberate will co-write this spec. Canal Plus U.S. Technologies, OpenTV Inc. and PowerTV Inc. will assist and act as watchdogs, a critically important role.

In the PC world, middleware is analogous to Netscape Communications Corp.'s "Navigator," or Microsoft's "Internet Explorer," or any other browser. It runs on any operating system. The execution environment consists of the plug-ins you download to listen to music, or watch a video, or play a game. The presentation environment is HyperText Markup Language (HTML). Applications developers write code without having to know what kind of equipment people use.

In TV, middleware is Canal Plus, Liberate and OpenTV, among others, who created an industry around it; Microsoft and PowerTV handle both operating systems and middleware.

Middleware providers sell MSOs two things: a "client" that sits in the set-top, on top of the operating system, and a "server" that doles everything out, and is usually located at the headend.

Most middleware companies provide a suite of get-started ITV apps: A branded first-screen, that links to e-mail, community info, the guide and the weather. This is the stuff you've seen at trade shows.

To apps writers, middleware companies provide tools that enable the "write once, run anywhere" mantra we so often hear.

What makes this all so confusing is that suppliers approach middleware in different ways. Some bind it to their own operating system. Others don't. But this is nothing new-almost all equipment used in cable is feature-differentiated.

Over time, through deployments and the OpenCable process, middleware will gain shape. MSOs will put boundaries around features. Apps will start rolling in. It'll be hard, but the alternative is subscriber churn, to the interactive features that direct-broadcast satellite offers.

Stumped by jargon? Heard some tech gibberish that makes no sense? Ask Ellis. Send your request to, with "Translation please" in the header.