Releasing software with a GTK front end

[James Johnson <johnsjam comcast net>]

Hello,

	My company is currently considering using GTK as a front end for a 
product.  My question lies in the open source part of the usage of GTK, 
how do companies that make things like Tivo for instance use linux 
libraries and not release there propietary inner working code?  What 
would my company need to do to do this?  We would be happy to release 
certain portions of the code but there are some propiertary parts of 
the code that we couldn't release.  Has anyone else dealt with this 
type of issue before?

Thanks,
James