A few proprietary systems are used for private communications.

No one wants to buy a proprietary system anymore.

"They're all willing to work together because they realize that proprietary systems are a thing of the past," he said.

The history, culture and underlying technology of the Internet has pressed most proprietary systems to give way to open technical standards.

"I don't believe the world can go back to proprietary systems," he said.

We're using open protocols, based on real standards as opposed to proprietary systems.

Further software evaluation will be carried out in 1993, to include proprietary systems.

If it does, the computer industry will have moved to open operating systems, rather than proprietary systems, which has been the rule.

"They're in a tough situation because they have a proprietary system that's basically incompatible with those of their peers."

In contrast, Apple is a closed, proprietary system that gives nothing back to the open source community.