I'm wondering how is this very different from MS Office vs. LibreOffice...
Granted, latest incarnations of MS's products are a bit different with the (crappy) ribbon and all, but LO is quite similar to previous versions of Office.
And I'm talking both about UI, design and functionality. Think Excel/Calc functions, for example.
One is the visual design, and even the author agrees that it's probably too similar: http://news.ycombinator.com/item?id=3744356
The other is the idea/concept. Creating open-source versions of unique ideas is nothing new and I doubt you'll see much sympathy on this front.