No. Where did you get that idea? Did you not visit the site? Nvu works with Windows, Mac, and Linux.
Well i cheked the site and the first thing i did was to look at the Screenshots and they where toked from a mac computer (i dont want to read too mutch eng)
Right in the top middle of the home page, in large letters, it says, "The complete Web Authoring System for Windows, Mac & Linux." The first Screenshots page gives no indication whatsoever that "they where toked from a mac computer", or a Windows computer or a Linux computer. It's just a screenshot of the main Nvu user window.