Bare Bones Software has released version 8.7.2 of BBEdit, my preferred text editor on the Mac, and what I'm using to type these very words.
Besides bug fixes, the major new feature in this release is that
you can now scroll background windows with the scroll wheel on Mac OS X 10.5 Leopard.
BBEdit is $199 payware. Upgrades from 8.5 and 8.6 are free.
Upgrades from 8.0-8.2 cost $30 and upgrades from 7.x cost $40.
Mac OS X 10.4 or later is required.