3. Computer-readable media embodying instructions executable by a computer to: provide a first class library comprising a first plurality of classes of a first language; provide a second class library comprising a second plurality of classes of the first language each containing one or more of the first plurality of classes of the first language; provide a third class library comprising a first plurality of classes of a second language; provide a fourth class library comprising a second plurality of classes of the second language each containing one or more of the first plurality of classes of the second language; receive source code of the first language defining a third plurality of classes of the first language, one or more calls to one or more of the first plurality of classes of the first language, and one or more calls to one or more of the second plurality of classes of the first language; translate the third plurality of classes of the first language into a third plurality of classes of the second language; translate the calls to the first plurality of classes of the first language into calls to the third class library without modifying the calls to the second plurality of classes of the first language; and generate bytecode of the first language based on the source code of the first language, the second class library, and the first class library; and wherein the third plurality of classes of the first language are translated into the third plurality of classes of the second language based on the bytecode of the first language, wherein the calls to the first plurality of classes of the first language comprise calls to object classes or string classes or both, wherein the source code of the first language relies upon classes of the first class library, wherein the source code of the second language relies upon classes of the third class library, wherein the second plurality of classes of the first language normalize the interfaces of the classes of the first class library, and wherein the second plurality of classes of the second language normalize the interfaces of the classes of the third class library, wherein the fourth class library is such that classes of the fourth class library have the same method signatures as corresponding classes in the second class library, and wherein the translation of source code of the second language into source code of the first language does not require the translation of the fourth class library, but instead calls to a class of the fourth class library become calls to a corresponding class in the second class library with the same method signatures.
3. Computer-readable media embodying instructions executable by a computer to: provide a first class library comprising a first plurality of classes of a first language; provide a second class library comprising a second plurality of classes of the first language each containing one or more of the first plurality of classes of the first language; provide a third class library comprising a first plurality of classes of a second language; provide a fourth class library comprising a second plurality of classes of the second language each containing one or more of the first plurality of classes of the second language; receive source code of the first language defining a third plurality of classes of the first language, one or more calls to one or more of the first plurality of classes of the first language, and one or more calls to one or more of the second plurality of classes of the first language; translate the third plurality of classes of the first language into a third plurality of classes of the second language; translate the calls to the first plurality of classes of the first language into calls to the third class library without modifying the calls to the second plurality of classes of the first language; and generate bytecode of the first language based on the source code of the first language, the second class library, and the first class library; and wherein the third plurality of classes of the first language are translated into the third plurality of classes of the second language based on the bytecode of the first language, wherein the calls to the first plurality of classes of the first language comprise calls to object classes or string classes or both, wherein the source code of the first language relies upon classes of the first class library, wherein the source code of the second language relies upon classes of the third class library, wherein the second plurality of classes of the first language normalize the interfaces of the classes of the first class library, and wherein the second plurality of classes of the second language normalize the interfaces of the classes of the third class library, wherein the fourth class library is such that classes of the fourth class library have the same method signatures as corresponding classes in the second class library, and wherein the translation of source code of the second language into source code of the first language does not require the translation of the fourth class library, but instead calls to a class of the fourth class library become calls to a corresponding class in the second class library with the same method signatures. 4. The computer-readable medium of claim 3 , wherein all of the classes of the first class library have different method signatures from all of the classes of the third class library.