like everyone else said, the link's not about the UI. But on that subject, autocutsel (http://www.nongnu.org/autocutsel/ http://www.nongnu.org/autocutsel/) can

like everyone else said, the link's not about the UI. But on that subject, autocutsel (http://www.nongnu.org/autocutsel/ http://www.nongnu.org/autocutsel/) can keep all of your X11 clipboards synchronized, so that anything copied to the clipboard can be MMB pasted, and anything selected with the LMB can be Ctrl-V pasted.