Difference from 8.2 to 9.x

[Mike]

I recently started working for this company and within a week of working 
here there was already a break in. It was easy to spot since they were 
using an insecure version of bind, but I wasn't able to upgrade to a 
version higher then 8.2.3 because they other admin. is scared of 
incompatibilities and learning something new. I was hoping that someone 
could help me out on how much has changed from 8.2 to 9.x. What would I 
need to change on my servers if this upgrade was possible? And is it simple 
to do? All of our servers our Redhat 7.0 with bind 8.2.3 running on it. 
Thanks.

Mike
www.idba.org
IDBA - Internet DataBase Applications