Here the reply I received from John,
I use Parallels, Windows 8.1, and Expression Web 2.
However, the real answer is “Unless your website relies on FrontPage extensions, you need to migrate to a different web editor. If your website does rely on FrontPage extensions, you need to remove them and THEN migrate to a different web editor.”
There are lots of Mac web editors, but only one will match the functionality of ExpressionWeb: Adobe DreamWeaver. I avoid it, because it’s 900 bucks and takes a couple of years to learn. But it will use EW .dwt templates directly (or more accurately, EW adopted DreamWeaver Templates). I will muddle along until EW refuses to run: and I still have a Windows XP VM with FrontPage installed!!
However, unless you want to go into business maintaining major commercial websites, there are LOTS of choices, some more appropriate than others:
http://webdesign.about.com/od/macintoshhtmleditors/tp/macintosh-wysiwyg-editors. htm
http://www.tuaw.com/2011/06/15/ten-wysiwyg-html-editors-for-mac-os-x/
I used Adobe GoLive and have move to WordPress which is free. You can do blog and static pages. Easy to learn. I would not recommend trying to import your files, but copy over data and into the new format.