I'd almost word the ad like this: If you are a rockstar ninja coder then please don't apply.
If you can hold your own any two of C, Java, Lisp, Perl, PHP, python or any other mainstream language, you've found just like we did that in the end the differences between programming languages are smaller than the things they have in common and you have the willpower and stamina to become part of a team extending and maintaining a fair sized codebase then feel free to apply.
Bonus points if you are operating a website of your own with more than 1,000 visitors / day.
More bonus points if you have prior experience with large scale web applications.
Don't send us references of companies that you worked for, send us references from your co workers.
Programming is about creating something new (or at least enhancing something) and it is done almost literally by thinking it through and simply writing it logically. Things of enormous importance are built this way. That is cool.