At the moment, nearly all my client work has been developing Object Oriented Perl - some systems over 50,000 lines of code. I have to say that after that, going back to Tcl REALLY HURTS.
XOTcl gets a way towards providing better software engineering options. Given that one of my biggest gripes with Tcl is the lack of advanced data structures and the necessity for upvar's, XOTcl would allow me to design object libraries to be data structures for me. While not nearly as cool as Perl, if we could implement, for example, the entire gang of four set of objects & methods then OpenACS will be able to present itself as a far more serious and mature development environment.
Any comments or flames?