One way to migitgate the problems when client work is contributed is to work in as transparent a process as possible. Of course, this is not always possible, and many client packages will be so specific as to be of no use to others except academically. This is one of the reasons for my position that content management be split between the tcl apis and the user interface. Client requirements for content management interfaces are very specific, but the underlying services are very similar. Photobook seems to be this way, it was built to fufill a very specific need at Sloan. On the other hand the continuing improvement to the survey work Malte seems to fit in with a more generalize approach.
This includes solictiing feedback on the design of a package, involving community memebers working on similar projects, working from a publicly readable code repository, etc.
