RoughDraft is freeware.
Is RoughDraft still being developed
No - it's been gracefully retired.
Does RoughDraft run on Windows Vista or Windows 7?
I'm told it does, although I haven't tested it throroughly myself.
What about a Mac or Linux version of RoughDraft?
You can try running RD under Wine but I can't guarantee any particular function.
Can I insert page breaks in RoughDraft?
Unfortunately not. I've wrestled with this night and day but never found a way to do it. If you need chapters or sections that start with a fresh page you can do it by writing them as separate files, then using the "File > Print multiple files" menu item.