TopView is the first object-oriented, multitasking, and windowing, personal computer operating environment for PC DOS developed by IBM, announced in August 1984[1] and shipped in March 1985.

[2][3] TopView provided a text-mode (although it also ran in graphics mode) operating environment that allowed users to run more than one application at the same time on a PC.

IBM demonstrated an early version of the product to key customers before making it generally available, around the time they shipped their new PC AT computer.

[citation needed] Initially, compatibility with the extended features was limited mainly to IBM applications, along with a few third-party products like WordPerfect and VolksWriter.

[6] Most DOS programs did, however, support these functions and did allow the user to perform the cut, copy, and paste operations by using the TopView pop-up menus.

[3] As later versions of TopView were released, it was able to successfully make more challenging DOS apps run in a multitasking fashion by intercepting direct access to system services and hardware.

Importantly, support for swapping non-resident programs was added—onto the hard disk on all computers and into the high memory area on machines equipped with a 286 CPU.

[7] Version 1.12, introduced in April 1987, added support for the new IBM PS/2 series, their DOS 3.30 operating system, and their new PS/2 mice.

[10] TopView sold below expectations from the start, with many potential users already satisfied with cheaper, less memory-intensive terminate-and-stay-resident task switchers like Ready, Spotlight, and Borland Sidekick which didn't need a multitasking environment.

[12] Later in April 1992, IBM introduced OS/2 2.0 which included virtual 8086 mode and full 32-bit support of the Intel 80386 superseding even DESQview and other similar environments.

[13] BYTE also criticized TopView's memory usage, but stated that "you will find that most software written for the IBM PC is TopView-compatible".

Noting the low price and "innovative multitasking features", the magazine predicted that the software "will attract a lot of takers".