Secret software interfaces hidden in Windows and previously only available to Microsoft's own developers have been exposed to the wider developer community.

Using NSELib Namespace Extension Library, created by software engineering firm Whirling Dervishes, developers can create applications that reside in Windows Explorer.

Whirling Dervishes founder Henk Devos said: "During the development of this product, Whirling Dervishes revealed hidden Windows interfaces that are crucial to the development of such applications but which the existence of was denied by Microsoft.

"An example of such interfaces is the way these applications can manipulate the 'tasks pane', a section that is displayed on the left in Windows XP and contains items like 'Folder Tasks'."

A namespace extension is a virtual folder in Windows Explorer, such as Control Panel.

Microsoft uses the technology in the FTP client that ships with Internet Explorer in the Compressed folders application (used to display the contents of ZIP files) included in Windows XP and other applications.

In August 2002, the software giant was forced to disclose a number of hidden interfaces as part of an antitrust case settlement.

Devos insisted that other interfaces that were uncovered should also have been part of the settlement, but are now available to the larger development community through NSELib.

NSELib is available for Delphi and Visual C++, priced at $799.