Wikipedia
TabWorks is a shell for Windows 3.x and Windows 95 and was developed by Xerox's XSoft division. TabWorks organizes files into tabs in a notebook-like interface. It was distributed with PCs from 1994 to around 1997 by several companies, including Compaq and NEC.
The product was developed by XSoft, a division of Xerox PARC in Palo Alto, California, the prestigious computing research lab that invented the concepts of laser printing, the mouse, the Windows/Mac user interface and Ethernet networking.
The original concept of a tabbed book metaphor came originally from Xerox PARC. Tabworks was shipped in 1993. A business team was assembled to produce the product initially for Compaq Computers who was given an exclusive worldwide license. NEC also had an arrangement with XSoft.
The software was created to replace the Windows Program Manager (PROGMAN.EXE) on Windows 3.x and Windows 95 installations. It resembled a tabbed 3-ring notebook metaphor making it easier for novice users to navigate Windows. Over 9 million copies of the software were installed worldwide making it one of the most popular pieces of software in the world.
TabWorks was later acquired in 1996 by Citadel Computer systems who integrated it into their line of network security and desktop utility product lines. Citadel discontinued selling TabWorks in early 2001.