There's several approaches, but the one that just got mentioned, viz. eat first meal later in the afternoon (pre-workout) and finish late at night is the most popular one.
Another one is to condense the eating window even further.
Likewise, some do this every day, while others eat during a normal time window every other day and only do the IF every other day.
I'd heard about it on the blog from Michael Eades (proteinpower.com ) back in Sept '06. The appealing part was improved health parameters.
The best part for me was being able to really hit low calorie intakes again, since eating fewer meals is much easier for someone who only gets hungry when a meal is being eaten.
My version quickly became a 2 meal-a-day in the 'Ramadan' fashion = eat at 10am/10pm every day.
After 2 months it brought my metabolism down by a bit over 10%. Going from 2 to 3 meals brought it back up again, and I'm still eating that way (10am/5pm/10pm).
Supposedly there's no evidence for a drop in metabolism, but not everyone is the same.
However, since it was so freaking easy to keep calories on the low side, I still lost fat at a decent pace. A better reason to go back to 3 meals was boredom with eating so few meals. It's great though when you're extremely busy at work.