A method and system for compiling multiple source language files that share a common library. The common library is represented in a common language that can be used by multiple different source languages. Font end compiler systems read the common language files that make up the common library and the source language files that use the library. Additionally, the front end systems produce common language files. The common language files produced by the front end systems can be used in the common library. The common language files may also be supplied to a back end system or runtime environment that further compiles the common language file to an executable form and executes the file. At runtime, the common language file is used by the runtime environment to layout the objects and methods used during execution.