I have several projects all using a combination of open source software.

Castle

NHibernate

Rhino

MbUnit

log4net

Are the first ones that come to mind.

In some of these cases I am always running off the trunk which means I am building everything myself. This can get pretty complex to manage, especially when the code changes frequently. I'd like to hear from you how you are dealing with some of these issues.

How do you handle updates?

How do you manage your own changes?

How do you integrate it with your build process.