Cable Television Laboratories Inc. and its members are working on a revised version of the Open Cable Application Platform (OCAP), a standardized middleware specification designed to run applications on forthcoming OpenCable-compliant digital set-top boxes, industry sources close the situation confirmed.

Instead of an elaborate version of the middleware designed for pricey advanced cable boxes, the revised version would focus on the core elements of the original OCAP specification. It would be used to run inside "a next-generation, economically smart set-top box," a source said.

CableLabs spokesman Mike Schwartz on Friday said discussions about a revised version of OCAP are "premature" at this point.

Designed for advanced digital set-tops, a draft of the original OCAP spec was released for comment to the vendor community in March. A final specification has not been released. Schwartz said the status of that has remained unchanged.

Last September, CableLabs selected Microsoft Corp., Liberate Technologies and Sun Microsystems Inc. as OCAP's primary authors, with Sun handling the executable engine for interactive applications, and Microsoft and Liberate teaming up for the application presentation engine. Canal Plus U.S. Technologies, OpenTV Inc. and PowerTV Inc. were also appointed as contributing authors.

The revised OCAP, at a minimum, will include a Java Virtual Machine, plus extensions (such as security and channel tuning) for TV applications, sources familiar with the situation said. Under debate is whether it will include presentation engines such as Hypertext Markup Language (HTML). That decision could be left up each indiviual cable operator.

At the same time, the core version of the spec, say a version called OCAP 1.0, could evolve in phases to handle more features and functions. MSOs would also be able to port legacy applications to the OCAP 1.0 middleware, sources said, adding that the altered version of the middleware would also furnish a platform to usher in set-top hardware portability and open up retail channels, which is the overriding goal of OpenCable.