UltraEdit, the editor that outgrew Windows, and migrated to both Linux and OS X added another version and changed the licensing model so a standard licenses now let you download and install a mix of operating system version for up to 3 machines. This option makes the editor a much better alternative for developers operating and testing in many environments on virtual and real machines.
From a Mac perpective the editor still suffers from being designed around a single window where everything happens including working on multiple files. For someone used to working in multiple windows across monitors this feel cramped.
The editor itself is fast, flexible and feature rich, and for people working with the Linden Scripting language (lsl), there is an excellent maintainer of a socalled word file for syntax highlighting over at github. There is currently no support for the ossl language extentions, but most scripts use the strict lsl language as maintained by Linden Lab, so this many not be any big hurdle.
You can get more information about UltraEdit and download a trial version from this page.