I've started working in earnest on Wye, a free SIF Zone Integration Server. It is the successor to TinyZIS. The prime factor in the architectural choices that went into TinyZIS was making sure I wouldn't get bogged down before I got started. I stuck with things I already knew, and it was a major accomplishment for me to keep it fairly simple.
The big goal for Wye is to write something that can easily be packaged and included in Edubuntu, K12LTSP, and the OLPC server, so I have to be very disciplined about creating dependencies. The main technologies I'm using are Apache, mod_python, SQLite, and SimpleTAL (templates). I'll be heading to the Ubuntu Education Summit in Spain at the beginning of May, and I'm hoping to have this in good shape by then.