Can one be master of multiple programming languages or not?

Question

Is it possible to be an expert at multiple programming languages and platforms (e.g. C#/.NET, **Objective-C/Cocoa, Java/Spring...Hibernate) assuming you spend 5-10 years developing software with it.

Or is it always going to lead to being good at one thing and mediocre at the rest?

To put it in different words: To focus or not to focus in one development language/platform.

PS: Please don't bring up Jon Skeet as an example. We all know he doesn't have to even learn programming languages; programming languages learn from him. Our assumption is an average developer.

Answer 1

A lot of .Net Developers came from Java or C++ background. So, yes I have seen several developers work on different platforms. I have worked on C, C++, Perl, AWK, JBOSS/SEAM, LAMP, and .NET stacks. There are people who know more languages than myself. More importantly you should work on mid-large projects to fully get the experience. The fundamentals are the same. Every language or stack has the same challenges when it comes to concurrency, exception handling, etc,...

Answer 2

Yes. In fact, many programmers and other computer-related are required to be adept at more than 4 languages. Especially in web development, as much knowledge in as many programming languages is a asset.

Also, expanding on multiple programming languages expands a person's knowledge. New programming languages are popping up all the time, and sooner or later old languages will be overtaken by new ones.

It is good to be mediocre at many languages, and good at many other languages. Do not focus on only one, and do not focus on all of them.