Undaunted

Hey just wanted to say how much I love this plugin and it's integration into the core program. Two of my favorite pictures as examples: http://flickr.com/photos/undaunted/1364872177/ http://flickr.com/photos/undaunted/1265285401/ I actually like the effect more on non-portrait things like skyscrapers and shadowy areas, although it does do good work on portraits too as you can see in the first example. I love Paint.net but I was curious how to make a similar effect in other programs (moving to Mac soon), I see the blur but where does the glow come from?