It seems that multi-national language function becomes a necessary part of internationalization software no matter the operation system or notepad. In MFC application, generally we store the language resources to the DLL or XML files, then through fixed key read it. The principle of most Web projects is same, just the different store place. Following is the Flex application internationalization: store the language resource to database. When add one language what need to do is just add a field in the table. If you need please read the following article.