▁Windows ▁CE , ▁and ▁it ▁is ▁unknown ▁whether ▁the ▁desktop ▁version ▁performs ▁T RI M ▁at ▁all . ▁ ▁Other ▁implementations ▁▁ ▁ex F AT ▁was ▁a ▁propriet ary ▁file ▁system ▁until ▁ 2 0 1 9 ▁when ▁Microsoft ▁released ▁the ▁specification . ▁This ▁lack ▁of ▁documentation ▁ham per ed ▁the ▁development ▁of ▁free ▁and ▁open - source ▁drivers ▁for ▁ex F AT . ▁According ly , ▁ex F AT ▁support ▁was ▁effectively ▁limited ▁to ▁Microsoft ' s ▁own ▁products ▁and ▁those ▁of ▁Microsoft ' s ▁license es , ▁which ▁in ▁turn ▁in hib ited ▁ex F AT ' s ▁ad option ▁as ▁a ▁universal ▁exchange ▁format . ▁▁ ▁Inter oper ability ▁requires ▁that ▁certain ▁results ▁be ▁achieved ▁in ▁a ▁particular , ▁pre defined ▁way ▁( an ▁algorithm ). ▁For ▁ex F AT , ▁this ▁potentially ▁requires ▁every ▁implementation ▁to ▁perform ▁certain ▁procedures ▁in ▁exactly ▁the ▁same ▁way ▁as ▁Microsoft ' s ▁implementation . ▁Some ▁of ▁the ▁procedures ▁used ▁by ▁Microsoft ' s ▁implementation ▁are ▁pat ented , ▁and ▁these ▁pat ents ▁are ▁owned ▁by ▁Microsoft . ▁A ▁license ▁to ▁use ▁these ▁algorithms ▁can ▁be ▁purchased ▁from ▁Microsoft , ▁and ▁some ▁companies ▁ ▁including ▁Apple , ▁Google ▁and ▁S amsung ▁ ▁have ▁done ▁so . ▁However , ▁in ▁the ▁open - source ▁e cos ystem , ▁there ▁is ▁no ▁financial ▁in cent ive ▁for ▁open - source ▁vend ors ▁to ▁purchase ▁a ▁license ▁for ▁these ▁algorithms . ▁ ▁Reg ard less ▁of ▁whether ▁open - source ▁or ▁not , ▁Microsoft ▁stated ▁that ▁"