Ultima II

Ultima - I - III - IV - VI - VII - VIII - IX

The Ultima games are the most long-lived and successful in the CRPG genre largely because of the depth NPC and story interaction offers. You don't just ask characters you meet "Where's this?" or "Any rumors?"; You ask them about themselves, their lives, and the world around them. In the Ultima games, NPC's have virtual lives. They have personalities, concerns, goals, even schedules. - Justin A. Hussel in a Daggerfall review, now offline

I know little about these first three Ultima games. They came out between 1981 and 1983. Graphics were CGA, 1983 there was an updated version of Ultima I with featured EGA graphics. It is often recommended to play the Commodore 64 versions which have better graphics and a better feel.

The Exodus Project has released upgrades for Ultima II and III that fix some bugs, too. Graphics are converted to EGA, and III has midi music. There is also an upgrade for V that adds midi music.
Windows Native Ultima II is exactly that, a Windows port of the game engine. You need the original data files to run it.

Mac and Atari ST

In 1985, Ultima II was ported to the Macintosh and to the Atari ST. These ports were as similar amongst themselves as they were different from the other versions. Both were fully integrated in the respective OS, with windows and mouse support.

(The Atari's GEM was a pretty close copy of the Macintosh system, too close for Apple's taste. They sued, and subsequent versions of GEM had to be deliberately crippled, thus paving Windows' way to success.)

The two first Wizardry games had been ported in a similar way to the Mac the year before. For the Atari, it may well have been a unique experiment. The Atari version of the next Ultima game, Ultima III, was quite conventional.