Three Decades: From SuperMemo 1.0 to SuperMemo 18.0

• SuperMemo 1.0 (Error creating thumbnail: Unable to save thumbnail to destination) was written in 1987, using Turbo Pascal 3.0. It was written by Piotr Wozniak. It was the first ever computer implementation of spaced repetition (for details see: Writing SuperMemo 1.0 for DOS)
• SuperMemo 2.0 (Error creating thumbnail: Unable to save thumbnail to destination) written in 1988. It was released as shareware by SuperMemo World in 1991.
• SuperMemo 3.0 (Error creating thumbnail: Unable to save thumbnail to destination) was the first major rewrite of the program to support DOS-type windows and menus.
• SuperMemo 4.0 (Error creating thumbnail: Unable to save thumbnail to destination) introduced Algorithm SM-4 that would modify the function of optimum intervals to match student's performance.
• SuperMemo 5.0 (Error creating thumbnail: Unable to save thumbnail to destination) 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 (Error creating thumbnail: Unable to save thumbnail to destination) 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 (Error creating thumbnail: Unable to save thumbnail to destination) 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 (Error creating thumbnail: Unable to save thumbnail to destination) 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 (Error creating thumbnail: Unable to save thumbnail to destination) 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 (Error creating thumbnail: Unable to save thumbnail to destination) initiated a line of SuperMemo whose sole focus is incremental reading. The domain of multimedia was taken over by SuperMemo UX. 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 11.0 aka SuperMemo 2002 (Error creating thumbnail: Unable to save thumbnail to destination) gave incremental reading a significant boost by employing Internet Explorer to import articles from the Internet and for WYSIWYG processing of texts.
• SuperMemo 12.0 aka SuperMemo 2004 (Error creating thumbnail: Unable to save thumbnail to destination) added an array of tools for use with incremental reading. It was also the first incremental reading software to be released as freeware in April 2010.
• SuperMemo 13.0 aka SuperMemo 2006 (Error creating thumbnail: Unable to save thumbnail to destination) dramatically increased the power of incremental reading by adding a surprisingly simple concept: the priority queue. With the priority queue there is virtually no limit to the size of the learning material a student can tackle. High-priority material receives full protection from forgetting, while lower-priority material can still linger in the collection for opportune learning times. The priority queue also made it possible to add the now indispensable overload tools: auto-postpone and auto-sort. SuperMemo 2006 was the first SuperMemo to introduce a dedicated import filter for Wikipedia.
• SuperMemo 14.0 aka SuperMemo 2008 (Error creating thumbnail: Unable to save thumbnail to destination) added YouTube-based incremental video as well as tools for optimizing sleep and learning (originally known from SleepChart freeware). SuperMemo 2008 also made huge progress expanding the set of tools needed in visual learning.
• SuperMemo 15.0 (Error creating thumbnail: Unable to save thumbnail to destination) was 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).
• SuperMemo 16.0 (Error creating thumbnail: Unable to save thumbnail to destination) was made even faster and more reliable than SuperMemo 15. It worked better in Windows 8 and with Internet Explorer 11. It integrated all incremental learning techniques. It required fewer clicks to access individual options. It added dozens of options for improving incremental reading, incremental video, incremental audio, and visual learning. It boasted the longest bug-fix list in history of SuperMemo (over 1000 significant fixes).
• SuperMemo 17 (Error creating thumbnail: Unable to save thumbnail to destination) implemented a new repetition spacing algorithm: Algorithm SM-17. It shed a great deal of outdated functionality making it slimmer and faster. It also added concepts and neural review that help make learning more intelligent (e.g. when solving problems).
• SuperMemo 18 (Error creating thumbnail: Unable to save thumbnail to destination) adds 40 predefined themes (skins) to differentiate between collections and make learning more pleasurable. The interface is simplified. The algorithm is polished. Dozens of improvements focus on incremental reading, esp. the handling of concepts.