Mac OS 8.6 or later recommended. And text editors just don't do that. That's not their role in life.
Text editors appear to be descended from other platforms and earlier times.
The command line interface in which they performed these wonders itself evolved, growing more lines, a scroll back buffer, borders with scroll bars, finally achieving the exalted status of text editor, all within an operating system that required no more than the most basic of User Interfaces. BBEdit is clearly the result of this long chain of evolution, but is also thoroughly and completely a Mac program. I've designed them for custom databases. I depend on their predictability. That's why I Mac.