Using Languages Other Than C

Using a language other than C is like using a non-standard feature: it will cause trouble for users. Even if GCC supports the other language, users may find it inconvenient to have to install the compiler for that other language in order to build your program. So please write in C.

There are three exceptions for this rule:

• It is okay to use a special language if the same program contains an interpreter for that language. Thus, it is not a problem that GNU Emacs contains code written in Emacs Lisp, because it comes with a Lisp interpreter.
• It is okay to use another language in a tool specifically intended for use with that language. This is okay because the only people who want to build the tool will be those who have installed the other language anyway.
• If an application is not of extremely widespread interest, then perhaps it's not important if the application is inconvenient to install.