Some observations on the current trend of UI design

Desktop application

Compared to the UI in Mac OSX, the UI of Linux applications is usually not very attractive, but there are still some UI elements that make the applications a bit better.

• Minimal border thickness: borders are useful to separate out areas of different functionality. Over the years, we can see a trend of decreasing border thickness to just a line.
  
  For example, the Arduino application on Linux has no border thickness between the tool bar and the tab pane. It has a border between the editor the status bar, which, in my opinion, could be reduced. 
  
  The Chrome app is another example with thin lines as borders.