Sébastien's library gives the ability to easily create modal and non-modal windows and dialogs, which optionally capture their position and size to a cookie automatically.
Work on a Rails Plugin to simplify usage of Sébastien's code is underway.
From the author :)
I am Sébastien Gruhier. Thanks a lot for the article. Like you wrote this nice article, I give you a scoop :). I have done a new homepage for my project with a better documentation. My english needs to be corrected (it should be done this WE) but I give you the URL:
There are also some cool samples.
Specialized version for .Net
It's GPL licensed (with commercial licenses available) at our main product website; Gaia Ajax Website
Also there are some extra skins and stuff you can use etc if you're on Java or some other framework that doesn't compile together with ASP.NET or Mono...