Can you post your references to backup the statement "Java, the most popular OSS language by far, [...]"?

I'd also be keen to know how you define "OSS language".

A quick count of packages on my debian box shows there are some 40 times more packages requiring of the C library than of a java runtime. This probably isn't representative, but I bet I can guess 10 high profile C projects for every high profile Java project you can name.

I tend to agree with Matt. Popular at a certain point in time is one thing, while widely used is a different thing. We are running tons of code precluding Java's birthdate, so I'd say C/C++ still constitutes the majority of the code in use now-a-days. Also, there is a lot of code written in Perl or other scripting languages (Tcl/Tk, Python, PHP)...

{Fashionable / "en vogue"} != existing

It is much harder to make less strict and less consistent languages like C/C++/Perl etc. bug free, Java tends to nag you at compile time and at runtime if you mess up, it also produces stack traces which makes it much easier to expose bugs in Java and any attached native code. You can even get specialist analysis tools which can step through compiled classes to find common mistakes and highlight the mistakes in the source code.

I'd wager that you could plot a graph that relates the code quality of an OSS project to it's popularity with developers (rather than just users).

Matt, I must admit that I always take these "my code base is bigger than your code base" stats with a pinch of salt. It often depends on scope, on what code you reckon is important enough to count and how you count it, and I'm not sure how I'd go about coming up with anything definitive myself. Which is why I was vague on the exact numbers - and I don't think that the popularity of Java vs. C++ was the main point of the article anyway.

However, the source is http://www.google.com/Top/Computers/Programming/Languages/Open_Source/, if that helps. I think that this provides some metric for popularity, but I agree it doesn't necessarily equate to "most used". However, according to Fortify, it's very difficult to figure out how many OSS packages there are of any 'flavour' (SourceForge, I'm told, doesn't list major packages such as Apache, MySQL or Linux).

To put "popularity" in context, at the end of 2005 an Ovum analyst said "We estimate that there are over 200 billion lines of COBOL in production today, and this number continues to grow by between three and five percent a year” . Would that make COBOL a "popular" computing language?

As for what is an OSS language, Java and PHP feature in that Google directory reference bur COBOL doesn't. Is there a lot of OSS software written in COBOL? Probably not (but I'm now waiting for something like IBM to point out that there's a major COBOL OSS project on Aphaworks).