Development assistance for mixed-language sources

Development assistance for a program comprising code in more than one language, is provided appropriately for each language in an integrated development environment. The assistance can include syntax highlighting, structure analysis, error reporting, completion assistance and/or context-sensitive help. The language of the subject element of code is determined and the appropriate assistance processes are applied. If the code is in a supplementary language, routines associated with the supplementary language are invoked to provide the assistance. When needed, information from other parts of the program file is provided to determine the appropriate assistance for the element of code.