System 7.0

System 7.0 was released in May 1991. System 7 (codenamed "Big Bang" and sometimes retroactively called   Mac OS 7) is a single-user   graphical user interface-based   operating system  for   Macintosh  computers. It was introduced on May 13, 1991 by   Apple Computer. [1]   It succeeded <span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">  System 6<span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">, and was the main Macintosh operating system until it was succeeded by <span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">  Mac OS 8<span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">  <span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">in 1997. Features added with the System 7 release included <span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">  virtual memory<span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">, personal <span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">  file sharing<span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">, <span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">  QuickTime<span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">, <span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">  QuickDraw 3D<span style="color:rgb(0,0,0);font-family:sans-serif;font-size:13px;line-height:19px;">, and an improved user interface.

<p style="margin-top:0.4em;margin-bottom:0.5em;line-height:19px;color:rgb(0,0,0);font-family:sans-serif;font-size:13px;">"System 7" is often used generically to refer to all 7.x versions. With the release of version 7.6 in 1997, Apple officially renamed the operating system "Mac OS", a name which had first appeared on System 7.5.1's boot screen. System 7 was developed for Macs that used the Motorola 680x0 line of processors, but was ported to the PowerPC after Apple adopted the new processor.