The techniques described herein include a mechanism by which users (such as software developers) can modify runtime libraries in a local workspace to display personalized translations of text of spoken languages in their programs via a browser interface. A server provides translation libraries to users with extracted text strings that can be used with one or more runtime libraries. Users can then customize the text strings in the translation libraries locally according to their specific needs, and those customized text strings can be sent to the server, merged with the original translation libraries, and then compiled into custom translation libraries, which are digitally encrypted and sent back to the users as an automated process that avoids many problems of conventional approaches.