Shareware

First Shareware application I recall was DOOM. As a shareware application it only came with a couple of free chapters and if you want to continue playing you must buy the full game. Shareware concept, from my point of view, revolutionize the software industry, from now on, applications came in a shareware mode, where some features will unlock until you buy the full application or if you don’t pay it, some functionality will be discontinued form the installed application.