Having taken a long break, where I was 'PerlMonks free' because I wasn't doing much Perlish, I have to say - I don't think it is less active.
Indeed, I think perhaps the opposite - there seems to be a fairly steady stream of things to read and respond to.
But in no small part, the reason I came back, is because I was looking up something to do with Perl, and found that Perlmonks had a variety of very useful and valid conversations on the subject. I must confess, I was a little surprised to find it healthy and well, but so it is. And I'm very pleased. There are perhaps a few fewer meditations and the like than there were. But then, perhaps Perl is getting more mature and stable. Perhaps 'elegant' code is getting better understood.
