Multiple projects, one CI codebase?

[eluser]2think[/eluser]
faulky,

I'm not sure if you meant 5 different applications as in things such as a forum, an address book, etc. all belonging to one domain. If that is what you meant, you could check out Modular Separation http://ellislab.com/forums/viewthread/121820/.

From my understanding, it is used by Phil Sturgeon in his Pyro-CMS and seems to be faster than Matchbox (another solution for modules).