▁closely ▁by ▁the ▁installation ▁of ▁a ▁new ▁application ▁that ▁either ▁conflic ted ▁with ▁existing ▁extensions , ▁or ▁installed ▁extensions ▁that ▁conflic ted ▁with ▁the ▁existing ▁set . ▁ ▁All ▁of ▁this ▁was ▁mit ig ated ▁by ▁the ▁ease ▁with ▁which ▁extensions ▁and ▁the ▁operating ▁system ▁itself ▁could ▁be ▁sw apped ▁in ▁and ▁out : ▁Instead ▁of ▁modifying ▁configuration ▁files ▁as ▁on ▁other ▁operating ▁systems , ▁extensions ▁simply ▁had ▁to ▁res ide ▁in ▁a ▁particular ▁folder ▁to ▁be ▁picked ▁up . ▁In ▁addition , ▁the ▁Mac ▁was ▁perfectly ▁happy ▁to ▁have ▁two ▁( or ▁more ) ▁system ▁folders ▁present ▁on ▁a ▁hard ▁drive . ▁Only ▁the ▁" bl essed " ▁system ▁folder ▁would ▁be ▁loaded ▁at ▁startup . ▁So , ▁when ▁a ▁new ▁version ▁of ▁the ▁operating ▁system ▁was ▁to ▁be ▁installed , ▁or ▁a ▁new ▁application , ▁the ▁user ▁could ▁easily ▁duplicate ▁the ▁system ▁folder , ▁perform ▁the ▁install , ▁and ▁then ▁fall ▁back ▁if ▁a ▁problem ▁resulted . ▁ ▁Ext ension ▁conflicts ▁came ▁to ▁an ▁end ▁with ▁the ▁release ▁of ▁Mac ▁OS ▁X , ▁which ▁uses ▁a ▁different ▁extension ▁mechanism . ▁Software ▁can ▁still ▁add ▁new ▁features ▁to ▁the ▁Mac ▁but ▁instead ▁of ▁extensions , ▁the ▁new ▁method ▁ent a iled ▁writing ▁startup ▁applications , ▁which ▁is ▁considered ▁sa fer ▁and ▁more ▁organized ▁approach ▁that ▁cannot ▁dest abil ize ▁the ▁machine . ▁ ▁See ▁also ▁ ▁Configuration ▁management ▁ ▁Dep endency ▁management ▁ ▁DLL ▁hell ▁ ▁References ▁ ▁Category : Ant i - pattern s ▁Category : Class ic ▁Mac ▁OS <0x0A>