1. A significant amount of time when computer programmers and others who are involved with software and hardware development; as well as, graphic designers, interface designers, and project managers, collaborate intensively on software projects or hardware components: Hackathons usually last a full day or up to a week.

Some hackathons are intended simply for educational or social purposes; in other situations, the objectives are to create practical software and electronic machines.

2. Etymology: a compilation of hack, in this application, "exploratory programming" + marathon, "a long period of time or challenging activities".