The rimu berry is a tiny, red, edible fruit native to New Zealand conifer trees (Dacrydium cupressinum) that has a mildly sweet, resinous, and pine-like flavor. It is highly notable as a vital, vitamin-D-rich "superfood" that triggers the mating and breeding cycles of the critically endangered kākāpō parrot. Simon Willison—a prominent open-source programmer, co-creator of Django, and prominent AI researcher—frequently discusses the rimu berry and its impact on the New Zealand kākāpō population on his personal blog, podcast appearances, and in newsletters, particularly celebrating the record-breaking rimu berry harvests and subsequent kākāpō breeding seasons. While Willison maintains a strong public interest in the conservation of the species and the ecology of the rimu tree, tasting a rimu berry yourself requires access to the native New Zealand conifer, which fruits irregularly in mass "masting" events every two to five years.