Since the original poster did not post any additional information about this particular release, let me add some.
This is not a major release, this version features a handful of notable changes and improvements including support for the NPRuntime plugin API extension. In addition, Mozilla 1.7.5 implements all the changes in the underlying Gecko code, such as "undetectable" document.all support, that have been implemented in Mozilla Firefox since Mozilla 1.7 and Firefox 0.9 were released in June.
The rendering capabilities of this new application suite software release should be identical to those of Mozilla Firefox 1.0.
Screenshot of Mozilla 1.7.5 under Mac OS X 10.3.7 "Panther"
