Full width tabs using Bootstrap (Support IE)

Twitter Bootstrap 3 contains a class for this, the nav-justified class.

Use it like so:

<ul class="nav nav-tabs nav-justified">
    <li><a href="#">Foo</a></li>
    <li><a href="#">Bar</a></li>
</ul>

Maybe I've found your solution:

Create that class with css:

.take-all-space-you-can{
    width:100%;
}

And then apply that class to your li tags into your ul. Doing these all the li takes the space that they can and automatically divide the space in the single row.

DEMO