[thelist] Designing Application Architecture URLs?

[Frank]

Since the beginning, I've taken the philosophy that applications should 
specialize; to do one thing, and do it well. This being the case, it also 
means that several specific applications should be able to talk and play 
with each other nicely. I've been able to accomplish quite a bit using the 
Fusebox framework, and for the most part, my work load has been reduced 
significantly, but I'd like to take it even further.

Can someone offer some suggestions, or pointers to URLs that discuss 
specific application architecture issues such as planning for unknown 
future application use, creating consistent methodologies for 
intercommunication (I guess that would be the equivalent of designing an API?)

Basically, I'm wondering if there is something similar to Application 
Architecture 101 that someone might know of. Suggestions? Thanks!