1. A computer system having a first program environment and a second program environment, said system comprising: a creating mechanism, said creating mechanism comprising means for creating a data description and conversion module, said data description and conversion module comprising first program environment data describing means and second program environment data describing means and means for converting data described by said second program environment data describing means into data described by said first program environment data describing means; a compiler, said compiler comprising means for compiling said data description and conversion module to create an executable conversion program; an invoking mechanism, said invoking mechanism comprising means for invoking said executable conversion program, said executable conversion program being invoked by a first program from said first program environment to share data stored by a second program from said second program environment; a parsing mechanism for parsing data descriptions from a particular program environment into source ADL (A Data Language) data descriptions; and a translating mechanism for translating said source ADL data descriptions into target data descriptions, said source data descriptions being ADL data descriptions for a program environment different from said particular program environment.