So Korean use original file extension.
First, Hangul(한글과 컴퓨터) replace Microsoft word. It use .hwp file, so our documents can not be read in other country.
Second, Alzip replace Winrar. Alzip support .rar or .zip file, but the default setting of Alzip is .egg file. Because of this, most of Korean use .egg file to zip file, so it can not be opened other country.
And there are some more, so it is uncomfortable to use laptop when visit Korea.
