Spurredonbytheinventionofthebluelight-emittingdiode(LED)aquarterofacenturyago,theLEDindustryhasadvanceddramaticallyandhasrevolutionizedthesignaling/signage,mobileandflatpaneldisplay,andmorerecently,generallightingmarkets.Indeed,LEDsnowout-surpassinperformanceallconventional(e.g.,incandescent,fluorescent,high-intensitydischarge)lightsourcesingeneralilluminationapplications.Thequestionarises:whatmoreistobedone?ThuscomesthethesisforthisspecialissueonLEDsandapplications.Fromthecontributedarticles,welearnthatLEDtechnologycontinuestoevolveandtransformitselfnotonlywithintheexistingapplicationsbutisalsopositioningforbrandnewapplicationstocome,bothofwhicharehighlightedhere.