Not all cabinets are made the same.  I was at the checkout counter at our local Wegman's.  I overheard a conversation about kitchen cabinets being the same.  Cabinets may all share the same function but they are very different.  

Frameless can be glued, screwed or doweled or all of the above.  Frameless has evolve with the use of Computer Numerical Control (CNC), that creates a tongue and groove which is much stronger than a dowel system.