It was launched on May 13, 1991, to succeed System 6 with virtual memory, personal file sharing, QuickTime, TrueType fonts, the Force Quit dialog, and an improved user interface.

In March 1988,[a][4]: XXIII–XXIV  shortly before the release of System 6, a group of senior technical staff and managers at Apple held an offsite meeting to plan the future course of Mac OS development.

Newly purchased Macintosh computers had System 7 installed and were often bundled with software such as HyperCard, At Ease and Mouse Practice.

Later, the Macintosh Performa family added various software bundles including ClarisWorks, The New Grolier Multimedia Encyclopedia, Microsoft Bookshelf, Spectre VR and Power Pete.

Since System 7 was introduced before the Internet came to popular usage, software such as MacTCP, FreePPP, and Netscape were not included.

Fat binaries, which contained the code necessary to run natively on both PowerPC and 68k systems, became common during this time.

Although most Macintosh models sold at the time included a hard disk as standard equipment, owners of older models were required to upgrade their hardware by buying either a new Mac or an external SCSI hard disk drive if they wished to run System 7.

System 7.0 was adopted quite rapidly by Mac users and quickly became one of the base requirements for new software.

It was common for Macintosh dealers to allow customers to use the store's demo machines to copy System 7 install disks for the cost of a box of floppies.

Apple continued charging for major operating system upgrades until the release of OS X Mavericks in 2013.

Soon after the initial release of System 7, the 7.0.1 minor update was released in October 1991, which updated the Portable and Brightness control panels, added the Caps Lock extension - which showed an up-pointing arrow on screen if the Caps Lock key was depressed on PowerBooks - and added the Cache Switch control panel in addition to RAM disk and sound management optimizations for 68040 systems.

Three small patches called "System 7 Tune-Up" also followed, which initially added the extension "System 7 Tuner" that improved memory management by quitting unused items, like applications and AppleTalk, and added "minimum" and "preferred" memory allotments to an application's "Get Info" box in its 1.0 version.

You had to buy it, much to the fury of user groups and online services that had gotten used to making each new system release available to everybody.

Backing down in the face of the protests, Apple eventually offered the System 7.1 upgrade kit to user-group and online service members for less than $30.

System 7.1 incorporated a huge number of changes, but the vast majority were deep-seated, core-level rewrites that added no usefulness to standard American Mac users.New to 7.1 is the Fonts folder.

System 7.1 also included a lot of internal changes to support the internationalization of dates, times, and numbers.

A set of specialized versions of 7.1, ranging from 7.1P1 to 7.1P6 (excluding 7.1P4) were created and included with various Performa models that were already available or were released after 7.1.

This release was a bundle of 7.1 with AppleScript tools, QuickTime and Apple Open Collaboration Environment (AOCE).

System 7.5.2, released only for the first PCI-based Power Macs, introduced Apple's new networking architecture, Open Transport.

New features include a revamped Extensions Manager, more native PowerPC code for Power Macs, more bundled Internet tools and utilities, and a more stable Finder with increased memory allocation.

[24] Through this period, Apple had been attempting to release a completely new "modern" operating system, named Copland.