▁( as ▁T tk ). ▁ ▁T ix ▁T ix , ▁the ▁T k ▁Interface ▁e X t ension , ▁is ▁a ▁set ▁of ▁user ▁interface ▁components ▁that ▁expand ▁the ▁capabilities ▁of ▁T cl / T k ▁and ▁Python ▁applications . ▁It ▁is ▁an ▁open ▁source ▁software ▁package ▁maintained ▁by ▁volunte ers ▁in ▁the ▁T ix ▁Project ▁Group ▁and ▁released ▁under ▁a ▁B SD - style ▁license . ▁ ▁It cl / In cr T cl ▁It cl ▁is ▁an ▁object ▁system ▁for ▁T cl , ▁and ▁is ▁normally ▁named ▁as ▁[ inc r ▁T cl ] ▁( that ▁being ▁the ▁way ▁to ▁increment ▁in ▁T cl , ▁similar ▁in ▁fashion ▁to ▁the ▁name ▁C ++ ). ▁ ▁T cl lib ▁T cl lib ▁is ▁a ▁set ▁of ▁script ed ▁packages ▁for ▁T cl ▁that ▁can ▁be ▁used ▁with ▁no ▁compilation ▁steps . ▁ ▁T k lib ▁T k lib ▁is ▁a ▁collection ▁of ▁utility ▁modules ▁for ▁T k , ▁and ▁a ▁companion ▁to ▁T cl lib . ▁▁ ▁t DOM ▁t DOM ▁is ▁a ▁T cl ▁extension ▁for ▁parsing ▁XML , ▁based ▁on ▁the ▁ ▁Ex pat ▁parser ▁ ▁T cl T LS ▁T cl T LS ▁is ▁Open SSL ▁extension ▁to ▁T cl . ▁ ▁T cl U DP ▁The ▁T cl U DP ▁extension ▁provides ▁a ▁simple ▁library ▁to ▁support ▁User ▁Dat agram ▁Pro tocol ▁( U DP ) ▁so ckets ▁in ▁T cl . ▁ ▁Dat ab ases ▁T cl ▁Database ▁Connect ivity ▁( T DBC ), ▁part ▁of