MacPaint was bundled with every Macintosh computer from 1984 to 1986. The program was used to create simple bitmap pictures and practically revolutionized the way graphics were done. A lot of today's high end graphic applications are distant descendents to good ol' MacPaint.
MacPaint works on all versions of 680x0 based Macintoshes from the 128k Mac to the Quadra series. Version 2.0 works with Macintoshes running System 7.01 or higher and can run on some Power Macintosh models.