OS/2

OS/2. OS/2 is a series of computer operating systems initially created through a joint development agreement between Microsoft and IBM. Intended to succeed the DOS operating system, it was designed as a protected-mode, preemptive multitasking successor with a sophisticated graphical user interface known as the Presentation Manager. Although it achieved notable success in certain corporate and banking environments, particularly with its robust IBM 3270 terminal emulation, it ultimately lost the broader market operating system wars to Microsoft Windows.

History

The development of OS/2 began in the mid-1980s as a collaborative project between IBM and Microsoft, following their successful partnership on PC DOS. The initial goal was to create a powerful operating system that could leverage the capabilities of the Intel 80286 and later the Intel 80386 processors. Key figures in its early development included Gordon Letwin from Microsoft and Ed Iacobucci from IBM. The partnership dissolved acrimoniously in 1990, with Microsoft focusing its efforts on the Windows 3.0 environment and IBM continuing development alone. Subsequent versions, like OS/2 2.0, were developed solely by IBM at its Hursley House laboratory in the United Kingdom. The project faced significant internal competition from IBM's own AIX and was eventually overshadowed by the success of the Microsoft Windows 95 launch.

Features

OS/2 was architecturally advanced for its time, featuring a hybrid kernel that supported true preemptive multitasking and multithreading in a single-user environment. Its object-oriented Workplace Shell interface, introduced with OS/2 2.0, represented a significant evolution from the earlier Presentation Manager. The system boasted a robust virtual memory management system, a high-performance HPFS (High Performance File System) as an alternative to FAT, and strong crash protection through memory isolation. It also provided excellent DOS compatibility, capable of running multiple DOS sessions concurrently in a virtual DOS machine, and supported the Windows 3.1 environment in later versions.

Versions

The OS/2 lineage began with OS/2 1.0, a text-mode-only system released in 1987. OS/2 1.1 added the Presentation Manager GUI. A significant milestone was OS/2 2.0 in 1992, a 32-bit operating system for the Intel 80386 that dropped the requirement for an underlying DOS. OS/2 Warp 3, launched in 1994, streamlined installation and included integrated TCP/IP networking. The final major retail version was OS/2 Warp 4 (Merlin) in 1996, which added Java support, enhanced Internet tools, and the VoiceType speech recognition software. Later updates, including OS/2 Warp Server and the OS/2 for e-business suite, were targeted at server markets.

Software

A wide range of software was developed for the platform, including the Lotus SmartSuite office productivity applications, the DeskMate GUI, and the Borland development tools like Borland C++. Notable native applications included the IBM Works suite and the Communications Manager. The system was a preferred platform for running complex IBM 3270 and IBM 5250 terminal emulation software for connecting to IBM mainframe and AS/400 systems. While major software vendors like Adobe and Corel initially supported it, with CorelDRAW being a flagship application, mainstream application support dwindled in the face of Windows 95 dominance.

Legacy and influence

Although commercially eclipsed by Microsoft Windows, OS/2 left a substantial legacy. Its crash-resistant architecture and advanced file system influenced the development of Windows NT, whose lead architect, Dave Cutler, had previously worked on similar concepts. Key components of its technology were integrated into other IBM products, including the LAN Server and IBM Workplace. The operating system found a long-lasting niche in automated teller machines, point-of-sale systems, and embedded controllers, particularly in industries like banking and aviation. Its development lineage continues through third-party commercial successors like eComStation and ArcaOS, which maintain the platform for specialized and legacy applications.