Safari mods to tags

I am debugging a couple of problems with dynamically generated web
pages on the Mac using the Safari browser. These problems (url having
a &ticket-xxx identifier) do not occur with Firefox.
First of all, I am testing to see if this issue occurs with other
versions of Safari. Is it possible to have multiple versions of
Safari coinstalled on a MacBookPro and will this cause new problems?
Secondly, I want to know if it is possible to find an IE installation
somewhere which I can install for testing.
Thirdly, how is the DOM a part of Safari? Maybe this might be the
source of my problems?
Please send me to simple web pages which explain how these tags are
appended to the url. My question is are the tag mods generated by the
jsp, or can they be addionally modified by the browser. I am
browsing several 1000+ page books for pertinent info.
I read http://en.wikipedia.org/wiki/Document_Object_Model
and a good article in ComputerWorld while in the "reading room"??
I understand enough about the web to be seriously dangerous and use to
be a web developer a long long time ago.