Companies provide proprietary extensions, modules, plugins or add-ons to an open-source package.

These (and similar) proprietary extensions are incompatible across different wi-fi chips vendors.

All scripting is based on Lua with proprietary extensions.

Vendors may support usage of higher frequencies as a proprietary extension to the standard.

By the mid 1990s, most network switch manufacturers had included aggregation capability as a proprietary extension to increase bandwidth between their switches.

However, almost all vendors have proprietary extensions that resolve some of this issue: they aggregate multiple physical switches into one logical switch.

Some of the 386 systems had proprietary 32-bit extensions to the ISA bus.

Also, when several vendors' equipment is deployed, the proprietary extensions are managed in a consistent manner.

The proprietary extension to Openfire allows multiple server instances to work together in one clustered environment.

A number of vendors provide some extremely powerful proprietary extensions.