I think KATE is best...
This is probably one of the best features for kate. [Mike Szczys] explains that there is a small column to the left of the code. Any line that is an opening bracket that column will have an arrow next to it. If you click the arrow it will fold all of the code between the opening and closing brackets. Very useful for large source packages.
250 Mb of overhead just to use the application. This is not just one package but several packages that are required to be on the system just to start the application. This may not be the best choice if you are using a net-book for development purposes on the go but if you have a Linux box at home this would do just fine.