title: is clipboard implemented by xlib or to be implemented by individual applications
body: <p>ICCCM defined three selections 1)primary 2)secondary 3)clipboard. But in the xlib, xatom.h had defined only XA_PRIMARY and XA_SECONDARY but clipboard has no such atom. So my doubt is whether clipboard is implemented by xlib or has to be implemented by individual applications like primary and secondary ?</p>
  
  <p>If it has to be implemented by individual applications, how different applications would interact with clipboard as in copy from one application's window and paste to another application's window..? How a common buffer is shared by different applications ? Can anybody help with the actual implementation of clipboard in linux..? I had gone through this <a href="http://www.jwz.org/doc/x-cut-and-paste.html" rel="nofollow"> link </a>. But I dint find much information about the implementation.</p>