Having a shared core and a lot of hooks for customization is the road we have taken for our application. I've written a lengthy post about it just last friday:

Having a shared core and a lot of hooks for customization is the road we have taken for our application. I've written a lengthy post about it just last friday: http://news.ycombinator.com/item?id=1557218 http://news.ycombinator.com/item?id=1557218