3 ▁output . ▁ ▁Ghost script ▁can ▁also ▁serve ▁as ▁the ▁back - end ▁for ▁PDF ▁to ▁r aster ▁image ▁( png , ▁t iff , ▁j p eg , ▁etc .) ▁converter ; ▁this ▁is ▁often ▁combined ▁with ▁a ▁Post Script ▁printer ▁driver ▁in ▁" virtual ▁printer " ▁PDF ▁cre ators . ▁ ▁As ▁it ▁takes ▁the ▁form ▁of ▁a ▁language ▁interpreter , ▁Ghost script ▁can ▁also ▁be ▁used ▁as ▁a ▁general ▁purpose ▁programming ▁environment . ▁ ▁Ghost script ▁has ▁been ▁port ed ▁to ▁many ▁operating ▁systems , ▁including ▁Unix - like ▁systems , ▁classic ▁Mac ▁OS , ▁Open V MS , ▁Microsoft ▁Windows , ▁Plan ▁ 9 , ▁MS - D OS , ▁Free D OS , ▁OS / 2 , ▁At ari ▁T OS ▁and ▁Am iga OS . ▁ ▁History ▁ ▁Ghost script ▁was ▁originally ▁written ▁by ▁L . ▁Peter ▁Deutsch ▁for ▁the ▁GNU ▁Project , ▁and ▁released ▁under ▁the ▁GNU ▁General ▁Public ▁License ▁in ▁ 1 9 8 6 . ▁Later , ▁Deutsch ▁formed ▁Al add in ▁Enter pr ises ▁to ▁dual - lic ense ▁Ghost script ▁also ▁under ▁a ▁propriet ary ▁license ▁with ▁an ▁own ▁development ▁fork : ▁" Al add in ▁Ghost script " ▁under ▁the ▁Al add in ▁Free ▁Public ▁License ▁( which , ▁despite ▁the ▁name , ▁is ▁not ▁a ▁free ▁software ▁license , ▁as ▁it ▁forb ids ▁commercial ▁distribution ) ▁and ▁" G NU ▁Ghost script " ▁distributed ▁with ▁the ▁GNU ▁General ▁Public ▁License . ▁With ▁version ▁ 8 . 5 4 ▁in