Understanding rogue waves is clearly quite important for marine safety. Hence while their existence has only been accepted for a few decades, a decent-sized body of academic work has sprung up. There was a Rogue Wave conference in 2000 [RogueWaves2000]. Theories about their existence include interference patterns (refraction/diffraction), current/wind interactions, and normal variations in the height of wave groups. These theories are problematic, however. Interference ought to produce a bell-shaped distribution, but high outliers occur much more often than that. Also, in the open ocean it is unclear what would cause an interference pattern. Current interactions don't explain the many rogue waves in areas without fast-flowing currents. Focusing effects of some type seem to be the most promising. They are difficult to analyze on messy real-life waves, but some non-linear mathematial models have produced focusing and shown promise at replicating the observed distribution [NorwayRogueGroup]. And the MaxWave team is starting a new investigation called WaveAtlas to further study the distribution of rogue waves.