With the explosion of interest in real-world use of functional programming, DEFUN is aimed squarely at practitioners: developers and technical managers who are using functional programming, or who are considering doing so. Attendees will learn how to achieve maximum benefit using functional programming from experienced practitioners, both from industry and academia. Talks provide concrete advice on how to tackle specific problems using functional programmings. Tutorials are forums for collaborative learning and hands-on practice of functional programming and function-programming techniques. Whereas the talks are pure presentations (with short Q&As), the tutorials are partly presentations, and partly "bring-your-laptop" sessions, where the tutorial presenter arranges practice problems for the participants to work on, and looks over the participants' shoulders.

Thus, the developer tracks are complementary to ICFP itself (which is for researchers). They are anchored by CUFP, the Haskell Symposium, and the Erlang workshop. Together, these events constitute a conference for developers that will promote participation by the growing community of professional users of functional programming technology.

DEFUN will have several tracks with the following types of presentations: