MixedLanguageProgramming is programming using code in several different languages.
This has been around for a long time and one of the classics has been to call from FortranLanguage to CeeLanguage or vice versa. This is not without its problems as the two languages have different design decisions on a number of issues, including strings and arrays. In this case both parts of the code are compiled with the correct compiler and then have to be linked together, including the correct libraries. The compilers have to be compatible and such a combination is available in the GnuCompilerCollection. Some tools for managing this process are available with the EclipseIde.
Some information on this approach is available at http://www.yolinux.com/TUTORIALS/LinuxTutorialMixingFortranAndC.html
Another approach is AlternateHardAndSoftLayers, where often interface code can be generated automatically using tools such as the SimplifiedWrapperAndInterfaceGenerator (SWIG) or the BoostPythonLibrary.