Internationalization of compilers and localization of programming languages is not a usual phenomenon yet; however, due to a rapid progress of software and programming technologies it is inevitable. The new versions of wide used programming systems already allow using the identifiers written in the native language, and partially supports Unicode standard, but still have many internationalization deficiencies. The paper analyses the main elements of internationalization of compilers and their localization possibilities. According to contemporary standards, existing practices of software internationalization and tendencies there are given recommendations how compilers should be internationalized. The paper gives arguments of the importance of localization of lexical elements of the programming languages, and presents solutions that enable to solve the problems of portability of programs developed using localized compiler as well as problems of compiler's compatibility with other compilers.