Have you ever used (or even seen...) Robertsons?
These are known in the US as "square" but they were actually developed by a Mr. P.L Robertson of Guelph ON who, I think still holds the patent on the design, but licences it to tool making firms. Robertson screws and drivers come in 4 sizes (#0 to #3 I believe) but the screwdrivers are also colour coded (and it is absolutely standard across any brand of driver - see the photos) and that's how everyone refers to them here:
0 = yellow (seldom used)
1 = green (often found in electrical boxes etc).
2 = red (the most common size)
3 = black (not often found except in heavy duty roles like holding the legs on a dining room table or securing the springs on a recliner chair)
The fit between the screw and the driver is amazingly good: you can walk around with a screw loaded on the driver and it won't fall off, and they are very difficult to strip. Nowadays, Robertsons are commonly used in Canada in furniture and electrical cabinets, but they aren't often found outside of the country. A buddy of mine lives in southern Germany in a Canadian made pre-fab house called a Viceroy (I think it must have been brought over there by a member of the Armed Forces in the 1970s). His entire house is put together with Robertson screws and he wanted to do some renovations but couldn't find drivers or replacement screws - so I sent him a set of drivers and a couple of boxes of screws.
Another funny story goes that around 1910, Henry Ford recognised the Robertson screw as far superior to the Phillips design, but he would only use them if old-man Robertson would sell Ford the entire company and the patents, so that he had an exclusive. P.L. wouldn't sell....and so the Robertson screw was doomed to obscurity in the frozen wastes of Canada, plus a few high furniture makers abroad. Much later, somebody invented the Torx(tm) bit and screw for automotive use - bit it is much more expensive to make than the Robertson.
Tools are fun!