These are some very creative solutions here. However, I'm with Don on this one: let's keep things simple. A naming convention for the packages is definitely a good idea. Two underscores maybe? Sebastian seems to have suggested this, and I think it's a good idea.
With respect to default values: I think the excessive use of PL/Tcl could be a bad idea from a performance standpoint. I'm thinking, like Don (maybe I should just let him speak :), that we can deal without default values. I will look over the source code some more to double check this.
Most importantly, I think we should try a simple implementation first. If we find that this might be incomplete and a real pain in the butt, we should by all means go with something more complete However, my current understanding of the source code is that this won't be too bad.
Opinions? Dissents?
