SuperMemo 2.0 () written in 1988. It was released as shareware by SuperMemo World in 1991.
SuperMemo 3.0 () was the first major rewrite of the program to support DOS-type windows and menus.
SuperMemo 4.0 () introduced Algorithm SM-4 that would modify the function of optimum intervals to match student's performance.
SuperMemo 5.0 () introduced Algorithm SM-5. It was adapted for commercial distribution by SuperMemo World in 1991. It was released as shareware in 1993.
SuperMemo 6.0 () was the second major rewrite of SuperMemo, and the first version written for commercial distribution. It was the first SuperMemo to interlink learning with the student's forgetting curve. It was also the first SuperMemo to garner a number of awards (e.g. Software for Europe 1992). SuperMemo 6 was released as freeware in 1995.
SuperMemo 7.0 () was the third major rewrite of SuperMemo as the program changed platforms from MS DOS (Turbo Pascal 6.0 for DOS) to MS Windows (Turbo Pascal 1.0 for Windows). SuperMemo 7 was initially considered buggy and few users were willing to switch. It soon, however, added some multimedia (pictures and sound), and became one of the most beloved SuperMemos ever. It collected many awards and topped many popularity charts in Poland. SuperMemo 7 was released as freeware in 1999.
SuperMemo 8.0 () was the fourth major rewrite of SuperMemo (1994-1997). It was based on ideas of hypermedia SuperMemo included in Wozniak's PhD dissertation "Economics of Learning" supervised by Prof. Witold Abramowicz of the University of Economics in Poznan. Only a fraction of the original code survived the transition from Borland Pascal to Delphi 1.0. The program was such a severe departure from the original idea of SuperMemo that it had to hide behind a code name Genius for 3 long years. SuperMemo 8 was very slow in convincing users of SuperMemo 7 to make a transition. It was distributed primarily as a shell for multimedia courses for learning foreign languages in Poland. It was also the first SuperMemo to be sold as a download via the Internet, however, back in 1997-1998 it found only a handful of customers.
SuperMemo 9.0 aka SuperMemo 98 () was finally able to lure users of SuperMemo 7. Despite being a decade old, only now SuperMemo finally offered a rich text formatting capacity. It also offered a long-range of new multimedia options. It was also the only SuperMemo in history that sold over a million copies as Multimedia SuperMemo partwork (e.g. Easy English). SuperMemo 98 was released as freeware in May 2005. It also branched off Multimedia SuperMemo that was later rewritten from scratch as SuperMemo UX (currently used as a shell for multimedia DVD courses produced by SuperMemo World). SuperMemo 98 was the first SuperMemo to reach a truly international audience as it became available for download via the Yahoo! Store.
SuperMemo 10.0 aka SuperMemo 2000 () initiated a line of SuperMemo whose sole focus is incremental reading. The domain of multimedia was taken over by the SuperMemo UX line. Incremental reading was promoted under the banner "read thousands of articles in parallel", which naturally met with major skepticism. Fewer than 5% of users of SuperMemo 2000 tried incremental reading, and there were fewer than a dozen of true believers and practitioners in those early days.
SuperMemo 15.0 () is the fifth major rewrite of SuperMemo (and first in 15 years). Now SuperMemo supports Unicode internally, which should make life easier for students of languages and for international users. As an extra bonus, SuperMemo code was simplified and made faster (esp. in processing texts).