Hi,
Within web player, the OpenUrl() is sadly lacking the option to define the Target so that we can open a new tab or a new page instead of replacing the content.
Is there a way to do that straight or should I implement this via Application.ExternalCall and write a litle function in javascript?
bye,
Jean
There is no built-in support for this, so yes, you need to implement this using Application.ExternalCall.
Still not possible. Unity 5.1

Still not possible.
Unity 4.5

This is terrible!
Please, vote on Unity’s feedback website: https://feedback.unity3d.com/suggestions/target-parameter-for-application … but don’t rise your expectations, this suggestion is there for FIVE years now 
use the method here Opening links in a Unity WebGL project and add ontouchend to your jslib file, should look like this…
var OpenWindowPlugin = {
openWindow: function(link)
{
var url = Pointer_stringify(link);
document.onmouseup = function()
{
window.open("http://www.xenz.org");
document.onmouseup = null;
}
var url = Pointer_stringify(link);
document.ontouchend = function()
{
window.open("http://www.xenz.org");
document.ontouchend = null;
}
}
};
mergeInto(LibraryManager.library, OpenWindowPlugin);
always a pleasure 