The distinction I remember from the time is that Shockwave player allowed 3D games (a use case that was later also filled by Unity Web Player) while Flash Playe

The distinction I remember from the time is that Shockwave player allowed 3D games (a use case that was later also filled by Unity Web Player) while Flash Player was just for 2D stuff. Also, Shockwave and Unity weren't available on Linux, unlike Flash.