Delta OS

The Delta Operating System (known as Delta OS) is a series of graphical operating systems developed, marketed, and sold by Kadishenware (formerly known as HagsBurg Electronics). It is suitable for home and business computers, also for educational, server services and gaming.

History
Due to high success of graphical user interface system protocols in HagsBurg, Delta Operating System quickly gained popularity in Pearl and some parts in Japan. Version 1.0 was released on May 13 1984, features overlapping windows, taskbar at the top, office suite known as Kiyosaki Office, command prompt, window buttons to the left, advanced calculator (includes hexadecimal numbers), support for 5.5 and 3.5 floppy disk format and notepad that can open files greater than 64kb. The license allows users to resell their copies, modifying them and distributing them, nowadays can be classified as free software license.

When the operating system first started its American market, HagsBurg was sued by Apple Computers for copying "look and feel".

Version 1.4 was released on 19 April 1989, included 256 color support, VHS video support, CD playback audio, 3D support, Internet support and

In 1991, HagsBurg implemented an operating system named DX, a variant of Delta Operating System running on top of modified Unix System V kernel, which is slightly more advanced than the mainline version of Delta OS. It includes X11 Window System, which would be ported to mainline Delta OS shortly thereafter.