3. A prettier UI
I've already noted LibreOffice 4.0's new support for Firefox themes, which Meeks told me was actually a request from a business customer, but there are also other UI improvements as well, including integration with Ubuntu's Unity desktop.
"Another big reason we call it 4.0 is the new UI layout," Meeks added. "Now we use Glade to design the UI in a way designers can use."
Improved accessibility and sizable dialogs are among the results, he explained.
4. Speed, and more speed
On a more practical note, LibreOffice 4.0 also brings significant performance improvements when loading and saving many types of documents, with particular improvements for large .ods and .xlsx spreadsheets and .rtf files.
5. Microsoft Office 2013
Much like Windows 8, Microsoft's new Office 2013 and 365 present users with a tough decision. Not everyone is convinced that the upgrade will be worthwhile, particularly in light of all the open options out there. I use LibreOffice every day, and would definitely say it's the fullest-featured and most attractive of those alternatives.
6. Free and open source
Last but certainly not least among the reasons for using LibreOffice is that it's both free and open source. What does that get you? In general, superior security, customizability, and interoperability, to name just a few advantages.