Wikipedia
Crosskart is a type of kart racing that takes place on autocross, speedway, dirt, or snow tracks instead of on paved tracks.
Competitions take place in classes that are based on cylinder volume (125 cc, 250 cc, or 650 cc). The 125 cc class is a junior class, open to those 12 years of age and older, but one can begin training at age 10. The 250 cc, and 650 cc classes are open to people above 16 years of age.
Erland Andersson of Sweden is said to have invented the Crosskart in the early 1980s. The idea was to create something that is safe, cheap, and easy to maintain, but still fun to ride. The Crosskart is basically a simplified version of Sprint car, Midget Car and Mini sprint
Crosskarting is probably most popular in the Nordic countries, although in southern Europe a similar motorsport with more powerful engines, Kartcross, exists.