How to choose programming language?

If the project is small project with single programmer then using BASIC stamp.

If the project is not samll and require multiple programmers, pure interpreter is not suitable and programming enviroment that support compilation such as C, C++ and Ada Compilers.

Improve execution time, using high level language, C++ and Ada language (both are object-oriented language), using technique called line-in assembly. 

Forth as low level language suitable for all type of projects. 

Java is the language whose role as embedded development(platform independance and object oriented language)