Windows/Mac/Linux: LibreOffice has always been powerful enough to stand up against Microsoft Office, but it's also been a bit ugly and clunky to use. A new update the overhauls the user interface and makes it a lot more useable.
The menu bars, context menus, toolbars, status bars and even the rulers are all completely redesigned. Likewise, the sidebar is a lot more useful and easier to use. Beyond that, there are plenty of under-the-hood improvements to go along with the new look, including a significantly better Track Changes feature in Writer, better import filters for a variety of apps, and a new OpenGL framework on Windows that improves transitions. If you've been avoiding LibreOffice because of its look and feel, now's the time to check it out again.