Which language?

When starting a project, the question you must answer is: Which language?

The answer is not simple.

If you're an Oracle shop then you are most likely comfortable with Oracle products and you should probably pick Java.

If you're a Microsoft shop then you will be comfortable with the Microsoft languages C# and F#.

If you're a Google shop, you may want to consider Google's Go language.

If you use Linux and open source tools, you may want to look at Perl, Python, Ruby, and JavaScript. Perl 6 has just been released, and may be a bit too "new" for serious enterprise projects. Python and Ruby are both mature, and JavaScript has a lot of support.

The interesting aspect here is that your choice of language is not about technology but relationships. All of these languages are capable. All of these languages have advocates, and detractors. None of these languages are perfect.

There are two other languages which you may consider. These are not connected with specific companies -- although implementations may be provided by companies. But the languages themselves are independent.

Those languages are COBOL and FORTRAN. Both are available from a number of sources, and for a number of platforms. COBOL is designed for financial transactions; FORTRAN for numerical computations. If your work falls into these categories, these languages are worth considering. (COBOL and FORTRAN are, however, not general-purpose languages and should not be considered for problems outside of their domains.)

Astute readers will note that I have omitted C and C++ from this discussion. If I were contemplating a move from Java to another language I would consider the above-listed languages before C or C++. And if I got to the point of considering C++, I would think very strongly about the STL and BOOST libraries.

All of these languages are capable. Each have advantages. A large consideration is the relationship that the language brings: Microsoft for C#, Google for Go, open source for Perl, Python, and Ruby. Don't ignore that.