Plain text editor.

Hey folks,

A question :].
I have the common problem of having to pass a parameter to the kernel at
boot to specify my boot slice (are those the correct terms?).
Anyway, I have found excellent instructions on how to add an entry to:
/Library/Preferences/SystemConfiguration/com.apple.Boot.plist
to allow this to happen automatically. I know what entry to add and I think
where to put it.
It is reported that I need to use a plain text editor to do this.
Unfortunately I don't know what they are called and how to start one.
Any info would be just neato.
I've spent a few hours trying to find out.

Best Wishes,
David Walker