If I was being unkind (and after the last couple of days working with TWiki I’m inclined to be) I’d say that the TWiki code shows all the signs that it has been written by people who know just enough perl to get into trouble and just too little perl to know how to get out of it.
One does have to admit that best practices like using the three-argument form of open
or the block-adorned form of exec
aren’t entirely obvious, though. There definitely is such a thing as too much DWIM; my hope is that Perl 6 will clean up a little here.