This plugin helps you control versioning of your cookbooks and also prevents you from accidently commiting things you don’t want to.
$ gem install knife-spork
Obviously this is a connector to ec2. I use Amazon ec2 so i am biased
$ gem install knife-ec2
A preflight plugin for Chef::Knife which lets you see which nodes and roles use a particular cookbook before you upload it.
$ gem install knife-preflight
A plugin for Chef::Knife which will diff the cookbook versions of two or more environments.
$ gem install knife-env-diff
Threaded bootstrapping of aws nodes
Search for more knife plugins:
$ gem search -r knife-