The Onion-model.
Once upon a time there was an Organ. An organ is a musical instrument. It is a big musical instrument; but this organ in particular was rather small specimen, albeit formidable: two yellowing rows of keys, a multitude of pedals, and an intimidating array of copper-knobbed stops and buttons all over the console. This was only the user interface; the large pipes and small pipes ran this way and that all over the Onion-model (it was in the Onion-model) and filled most of it. The space as you might imagine was not very big to start with: the largest space was a cylindrical hallway down the center with the longest and biggest of the pipes situated along it. At the back there was the engine. At the front there was the console for the organ and the rest of the controls, and a round, porthole-like window that was the only window in the space-ship. The walls were paneled with wood and the fixtures for the pipes were copper. A low rumbling sound permeated the entire structure; take-off w...