Languages

1. Scheme/Lisp. If you come from a ?curly braces? background you should learn a functional language.
   As Eric Raymond says about the very similar Lisp:
   LISP is worth learning for a different reason ? the profound enlightenment experience you will have when you finally get it. That experience will make you a better programmer for the rest of your days, even if you never actually use LISP itself a lot.
   I prefer Scheme because it is purer (no need for funcall).

2. Erlang. Another functional language. Concurrency done right. In the multiprocessor future this could be very important indeed.

3. Ruby. A conscious attempt to make a programming language that is a joy to use. String handling from Perl, OO from Smalltalk, closures from Lisp/Scheme.

4. Javascript. The only way to create a rich UI in current web browsers.

5. C. For when things must be fast. Use with Ruby, Python and many other languages when you need to optimize a section of your code for performance.