Remember back when the Internet Archive was not much more than a cache of old defunct websites. The Archive back then was just called the Wayback Machine, which it still calls its search box. Since then the archive has expanded to include books, software, videos, music, and more. Some of the most recent additions to the site have included emulators of various types from the ColecoVision to the Commodore 64.
The Internet Archive's latest emulator is for early Macintosh computers. According to the Verge, just today the site has added a collection of 45 games and other software from the early days of Apple. Just a small sampling of what the library has includes Sierra Championship Boxing, Dark Castle, Airborne!, MacPaint, MacWrite, and full emulations of the MacOS System 6 and 7.0.1 operating systems. All of the software is emulated within the browser, so no external software or downloads are necessary.
It is interesting to look at the dated simplistic gameplay and remember a time when entertainment value was not dictated by the quality of the graphics. Some of the younger folks these days would not spend five minutes with most of these games, but for the older generation, many of these titles bring back memories and are still quite fun to play. If old Mac software does nothing for you, check out the Archive's arcade games. These cabinet classics like Out Run and Joust are emulated in their full original arcade-machine glory.