Although one of the disadvantages of a single-engine configuration is its limited growth potential there are exceptions as demonstrated here by this F-16 equipped with conformal fuel tanks, air-to-surface and air-to-air weapons, and internal FLIR sensors.

Так конструкторы "Боинга" видят еще один вариант JSF
In contrast with the F-22, which is powered by two P&W F119 engines, both the Lockheed and Boeing JSF contenders (this artist’s concept illustrates Boeing’s USAF variant) use a single engine - a derivative of the F119 is sufficiently powerful and is the obvious choice for these projects where low cost is a crucial design goal.

Somewhat surprisingly the AIDC Ching-Kuo uses two TFE1042-70 turbofans to provide similar thrust and roughly equal performance to the Gripen. Perhaps the specification emphasises survivability.