This is in Firefox; I tried holding down the <Esc> key to prevent the jump, but it jumped anyway. Finally I was able to open http://linuxlibertine.sourceforge.net/Libertine-EN.html#xelibertine in Internet Explorer and hold the <Esc> key down until it gave up trying to jump. Maybe other browsers are better behaved.
The link on http://www.linuxlibertine.org/index.php?id=89&L=1 to the xetex documentation (under the title "Manual to the XeTex-Package") takes you to a page http://linuxlibertine.sourceforge.net/Libertine-EN.html#xelibertine that appears to have a download link for the PDF (actually, it's labeled "LaTex directory", so it's not obvious that's where you should go). But before you (or at least I!) can click on the link, the page jumps to http://www.linuxlibertine.org/, and the back arrow doesn't work.
This is in Firefox; I tried holding down the <Esc> key to prevent the jump, but it jumped anyway. Finally I was able to open http://linuxlibertine.sourceforge.net/Libertine-EN.html#xelibertine in Internet Explorer and hold the <Esc> key down until it gave up trying to jump. Maybe other browsers are better behaved.
I think the proper behavior of the link in the "Manual to the XeTex-Package" para would be to jump directly to http://linuxlibertine.sourceforge.net/latex/, without going through http://linuxlibertine.sourceforge.net/Libertine-EN.html#xelibertine. And the proper behavior of http://linuxlibertine.sourceforge.net/Libertine-EN.html#xelibertine would be to not jump to http://www.linuxlibertine.org/.