1. A method to execute a computer program written for a first computer architecture on a second computer architecture in which a source code for the computer program has been compiled into byte code of a first type by converting the byte code of the first type and markup language into byte code of a second type when there is direct mapping of the data elements of the first type of byte code to data elements of the second type of byte code, wherein when there is no direct mapping of at least some of the data elements of the first type of byte code to data elements of the second type of byte code, a bridging byte code is inserted into the second type of byte code, the method comprising: receiving a first byte code for a computer program at a byte code interpreter of a computer system, wherein said first byte code is of said first type and contains one or more data elements of said first byte code type; receiving a markup language code at said byte code interpreter of said computer system, wherein said markup language code refers to at least one said data element in said first byte code, wherein the markup language data elements comprises data structures defining colors, lines, shapes, text and layout position in markup language code; referencing at least one byte code mapping library at the byte code interpreter, wherein said byte code mapping library contains one or more instructions for mapping one of said first byte code data elements of said first type to one or more of said second data elements of said second byte code type, or a bridging byte code only when there is no direct mapping of data elements in order to compensate for a lack of programming constructs equivalence between the first byte code and second byte code; mapping at least a portion of said first byte code data elements to one or more second data elements of said second byte code type or inserting a bridging byte code; converting said markup language code into one or more markup language data elements; referencing at least one markup language mapping library, wherein said markup language mapping library contains one or more instructions for mapping one of said markup language data elements to one or more said second data elements of said second byte code type, wherein the markup language data elements comprises data structures defining colors, lines, shapes, text and layout position in markup language code; mapping at least a portion of said markup language data elements to one or more second data elements of said second byte code type or inserting a bridging byte code; converting at least a portion of said second data elements into said second byte code; and, executing the computer program using the functional aspects of the byte code of the second type and the display aspects of the markup language from the second byte code.