Question: Is there an alternative tool similar to [MS Reader](http://www.microsoft.com/reader) that allows one to both **publish** and **view** ebooks in Linux, Mac and Win?

Answer: 
Perhaps [Calibre](http://calibre-ebook.com/) will do the trick for your needs. It's a rather comprehensive eBook manager/reader/converter.
Just save your files as PDF. That's the most cross-platform you'll get (all OS + all phones, handhelds and web)