Versions of gtk/gtkmm used by distros?

[Bryce Harrington <bryce bryceharrington org>]

Hi,

For Inkscape we're considering changing our required gtk/gtkmm
requirements from 2.4 to something newer (e.g. 2.8).

Could someone point me at a listing of which distros ship with which
version of gtk?  We're attempting to gauge how many users would be
affected by this change.

Thanks,
Bryce Harrington
http://www.inkscape.org