Many years ago, the University of Tennessee developed a new type of computer that made permanent marks on a piece of paper. This was a huge advancement over the display-based computers of the day, because the data didn't disappear when you turned off the computer. In fact, 'SIL' stood for "Send It Later!" which was their marketing slogan, referring to the fact that you could work on something for a bit, stop, then come back to it later and still have the data just as you left it.
Because of the U.Tenn origin, they collectively known as "UTenn-sils." The original was quite heavy, hence the nickname "ton-sil," but the ton-sils didin't really do much and frequently developed problems, so most of them were quickly removed from service. U.Tenn dropped out after that fiasco, but the University of Pennsylvania picked where U.Tenn left off. The "penn-sil" was lighter and had a soft pink 'erase' button that allowed some basic editing. As I recall, the erase button would wear out after too much use.
Microsoft dabbled with their own version, test-marketing names like "Vista-sil" and "XP-sil" and "DOS-sil", but the focus groups complained that none of those sounded like real words. Eventually they stumbled across "Window-sil," which did very well in the focus groups. By that time, of course, Microsoft had decided to get out of the hardware business. As I recall, they found some other use for the "Window-sil" name (shortened a bit, I think), but I can't remember what they used it for.
