Pilots then build kites just for themselves, it was way too complicated to get molds and plans across the country towards other pilots. Things changed for the better with the wide spread use of the internet. Although many kites were available as a plan and "free to build and use", not one of those was capable of flying the tricks that people wanted to do then.
Christian Derefat designed "Le Virus", the first trick kite one could build that was loaded with tricks! The plans were on the internet and could be downloaded and used. Pretty soon a lot of "Le Virus" kites were popping up in pictures all over the globe. As mister Derefat soon develloped other kites (Neutron, Diablis, Vortex, to name but a few), other pilots decided to take on the concept and design their own likings of trick kites. Werner Hulstaert could move on from his long time devellopment, the B'zar, while guys like Frederik Strobbe found inspiration in Prism kites and the likes.
Other people helped out a lot, by creating the tutorials on how to build those trick kites, making all this available on the internet and giving seminares and workshops on the subject (take a look at the website from Tom Degryse)