PageEdit is described as 'An ePub visual XHTML editor based on Sigil's Deprecated BookView' and is an app in the News & Books category. There are three alternatives to PageEdit for Mac, Windows, Linux and PortableApps.com. The best alternative is Sigil, which is both free and Open Source. Other great apps like PageEdit are Jutoh (Paid) and Moopato eBook Writer (Paid).
Moopato eBook Writer is a desktop tool for writing eBooks with the focus on your writing. It has a minimalist UI for distraction free working. The eBook layout is done with templates and separated from your writing. You can write in markdown.