Selling services using GPLed software

[Nikola Skoric]

It seems to me that only case in which you are obligated to provide
sorce code is if you are distributing your application. But, what
about web apps with which you can make money without distributing
them. For instance, www.conquerclub.com is developed around phpBB3,
and www.travian.com is developed around phpBB2. And both of them are
making money with their software, but they do not provide their source
code. Is there any part of GPL forbidding that?

-- 
"Now the storm has passed over me
I'm left to drift on a dead calm sea
And watch her forever through the cracks in the beams
Nailed across the doorways of the bedrooms of my dreams"

 LocalWords:  GPLed software Organization Reply Followup Sarma