In the early '80s, guitarists started modifying their Strats by putting humbuckers in the bridge and/or neck position. Then companies like Charvel brought out custom replacement parts and started making even more souped-up offset-double-cutaway (Strat-style) guitars.
Next came rear-routed electronics, locking trem systems, hotter pickups, neck-thru construction (in the form of the Jackson Soloist), deeper cutaways, sharper contours, pointier headstocks, more sophisticated electronics and switching, and so on.
These types of guitars go beyond what the original was designed to do, but they aren't entirely original designs. Since they owe so much of their design to the original innovator, they are generally referred to as "Super Strats".
The RG is just Ibanez's evolution of the offset-double-cutaway bolt-on guitar design, but it still has its roots in Leo Fender's original design.