Abstract: Method for enabling the simultaneous use of a first and a second programming language within a computer program, and apparatus to practice the method. To enable this sharing of languages, the present invention first provides for a common runtime representation of the data between the several languages in a program as a shared object model. The shared object model includes the layout of complex data structures (e.g., classes), the creation of data, the calling conventions, the destruction of data, the runtime representation of type information, dynamic function call dispatch, and dynamic type conversions. The use of a shared object model enables the sharing of the several compilers' internal representation of data between the different languages as a persistent shared symbol table. This shared internal data representation enables the several compilers to define their respective internal data representations in terms common to each of the compilers.