▁ 2 0 0 5 ▁in ▁Las ▁Veg as , ▁May ▁ 9 – 1 2 , ▁ 2 0 0 5 . ▁Microsoft ▁offered ▁main stream ▁support ▁for ▁Windows ▁Mobile ▁ 5 ▁through ▁October ▁ 1 2 , ▁ 2 0 1 0 , ▁and ▁extended ▁support ▁through ▁October ▁ 1 3 , ▁ 2 0 1 5 . ▁It ▁was ▁first ▁offered ▁on ▁the ▁D ell ▁A xim ▁x 5 1 . ▁It ▁used ▁the ▁. NET ▁Comp act ▁Framework ▁ 1 . 0 ▁SP 3 , ▁an ▁environment ▁for ▁programs ▁based ▁on ▁. NET . ▁Windows ▁Mobile ▁ 5 . 0 ▁included ▁Microsoft ▁Exchange ▁Server ▁" push " ▁functionality ▁improvements ▁that ▁worked ▁with ▁Exchange ▁ 2 0 0 3 ▁SP 2 . ▁The ▁" push " ▁functionality ▁also ▁required ▁vendor / device ▁support ▁With ▁A K U 2 ▁software ▁up gr ades ▁all ▁WM ▁ 5 . 0 ▁devices ▁supported ▁Direct Push . ▁This ▁version ▁featured ▁increased ▁battery ▁life ▁due ▁to ▁Pers istent ▁storage ▁cap ability . ▁Pre viously ▁up ▁to ▁ 5 0 % ▁( en ough ▁for ▁ 7 2 ▁hours ▁of ▁storage ) ▁of ▁battery ▁power ▁was ▁reserved ▁just ▁to ▁maintain ▁data ▁in ▁vol atile ▁RAM . ▁This ▁continued ▁the ▁tr end ▁of ▁Windows - based ▁devices ▁moving ▁from ▁using ▁RAM ▁as ▁their ▁primary ▁storage ▁medium ▁to ▁the ▁use ▁of ▁a ▁combination ▁of ▁RAM ▁and ▁flash ▁memory ▁( in ▁use , ▁no ▁distinction ▁between ▁the ▁two ▁is ▁obvious ▁to ▁users ). ▁Program s ▁and ▁frequently ▁accessed ▁data