▁The ▁hyper visor ▁was ▁put ▁in ▁quot ation , ▁because ▁both ▁of ▁them ▁have ▁similar ▁behavior ▁in ▁that ▁they ▁intercept ▁system ▁calls ▁in ▁a ▁different ▁mode : ▁user ▁mode ; ▁and ▁runtime ▁mode . ▁The ▁user ▁mode ▁intercept s ▁the ▁system ▁calls ▁from ▁the ▁runtime ▁mode ▁before ▁going ▁to ▁kernel ▁mode . ▁The ▁real ▁hyper visor ▁only ▁needs ▁to ▁intercept ▁the ▁system ▁call ▁using ▁hyper call ▁in ▁kernel ▁mode . ▁Hope fully , ▁once ▁Windows ▁has ▁a ▁Hyper visor , ▁Virtual ▁machine ▁monitor , ▁there ▁may ▁even ▁be ▁no ▁need ▁for ▁J RE ▁and ▁CL R . ▁Moreover , ▁in ▁the ▁case ▁of ▁Linux , ▁maybe ▁the ▁J RE ▁can ▁be ▁modified ▁to ▁run ▁on ▁top ▁of ▁the ▁Hyper visor ▁as ▁a ▁load able ▁kernel ▁module ▁running ▁in ▁kernel ▁mode , ▁instead ▁of ▁the ▁having ▁slow ▁legacy ▁runtime ▁in ▁user ▁mode . ▁Now , ▁if ▁it ▁were ▁running ▁on ▁top ▁of ▁the ▁Linux ▁Hyper visor ▁directly , ▁then ▁it ▁should ▁be ▁called ▁Java ▁OS , ▁not ▁just ▁another ▁runtime ▁mode ▁J IT . ▁ ▁M end el ▁Rosen bl um ▁called ▁the ▁runtime ▁mode ▁a ▁High - level ▁language ▁virtual ▁machine ▁in ▁August ▁ 2 0 0 4 . ▁However , ▁at ▁that ▁time , ▁the ▁first ▁type , ▁intercept ing ▁system ▁calls ▁in ▁user ▁mode , ▁was ▁ir respons ible ▁and ▁un th ink able , ▁so ▁he ▁didn ' t ▁mention ▁it ▁in ▁his ▁article . ▁Hence , ▁Application ▁Stream ing ▁was ▁still ▁myster ious ▁in ▁ 2 0 0 4