Infinite Mac boots real classic Mac OS releases — System 6 through 9 — directly in the browser, with period software like MacPaint, MacWrite, and HyperCard already installed and nothing to configure. Pick a machine from the customize menu, anywhere from a beige Macintosh SE running System 7.5 to a colorful Mac II, and it opens onto an actual working desktop. A CD-ROM library and drag-and-drop file import round out the trip back.