Not so long ago, in order to achieve such effects, we used JS. But, now, CSS3 has all the necessary tools for making pop-up windows too.
Singup / Login Forms
Very Easy to costumize.
Very Easy to Integrate & Use
Modern Browser Support
Background from the preview is downloaded from subtlepatterns
If you like, don’t forget to rate it!
ChangeLog19/02/2013 – Version 1.1
Added password recovery
Update video review and screenshots
18/02/2013 – Version 1.0