I'm doing a presentation about history of software engineering and stuck at this question due to the lack of available information. According to my quick research, TopLink is the first ORM framework ever created (in 1990s, certainly before 1996). If anyone else has a different opinion, please let me know. (Please also provide a link to the reference sources) Ref: http://en.wikipedia.org/wiki/List_of_object-relational_mapping_software http://en.wikipedia.org/wiki/TopLink