OK, here's what : I've programmed in over 20 different languages and now, because of a large project I'm currently working on for Mac OS X (in Objective-C/Cocoa), I need to make a final decision on which language to use for my background scripting + plugin functionality.

Definitely, one factor that'll ultimately influence my decision is which one I'm most familiar with, which is PHP (one of the ugliest languages around, which I however adore... lol), then Python / Perl (the "proven values"... )... and then Ruby (which, to me, is almost confusing and I've only played with it for some time.)

Now, here's my considerations :

• (As previously mentioned) Being familiar with it (anyway, if X is better in my case, I really don't mind studying it from scratch...)
• Speed
• Good interaction with the Shell + ease of integration with my Cocoa application

Btw, some of the reasons that made me wonder if Ruby would be a good choice is :

• The hype around it (although, I still don't get why; but that's probably just me...)
• My major competitor (we're actually talking about the same type of software here) is using Ruby for its backend scripting almost exclusively (ok, along with some BASH). Isn't Ruby considered slower e.g. than Perl? Why did he choose that? Simply, a matter of personal taste?

So... your thoughts?