What languages are not written in C?

Are all programming languages written in C?

Having said all that, the answer to your question is "No". C is based off of a language called ALGOL, and there were many competitors both with ALGOL (FORTRAN, Lisp, COBOL) and C (none come to mind).

Is Java written in C?

The very first Java compiler was developed by Sun Microsystems and was written in C using some libraries from C++. Today, the Java compiler is written in Java, while the JRE is written in C.

Is Python coded in C?

Python is written in C (actually the default implementation is called CPython).

Is C++ written in C?

Most compilers for C and C++ are written in C and C++. This is possible because of compiler bootstrapping.