Hello,

I was hoping to find out the most information a web site CAN gather
about its visitor. I know it can see the visitor's IP address, MAC
address, browser version, etc; I'd like to know the most possible
information the server can see (know), with and without java installed
on the client's browser (if that makes a difference). Thanks!

Hello billabong007-ga,

Thank-you for your question.

The answer depends a lot on the security that the user has enabled in
his browser when accessing your site.  Having javascript (please
remember javascript is not the same as java!) enabled or disabled does
not usually matter as you can normally use an alternative scripting
language to discover the information you require.  For my answer I
will assume that he has standard/minimal settings on his browser and I
have compiled the list below that details the main things you can
discover about your users:

· IP address
· Location of user's ISP
· Name of ISP
· Location of user (Continent, Country, City - approximate latitude and longitude)
· Timezone of user
· Date/Time they are visiting
· Length of visit
· Every page visited on your site
· Whether they have visited before
· Operating system
· Various paths to folders on your system
· Versions of programs being used on your system
· Name of your computer
· How you access the internet (through a proxy or not)
· What types of documents your browser is set up to accept
· Default language of your browser (language you probably speak)
· Site you visited last
· Number of sites you visited before getting to this one
· Various miscellaneous technical settings of your browser
· Number of processors in your PC
· Type of processor
· Port you are accessing the site through
· Any session variables or cookies that have been set
· What browser extensions they have enabled/disabled (for instance,
Flash, Javascript, PDF support etc)
· Size of users screen, number of colours etc

Using all this information together you can build up very detailed
profiles of each user that visits your site (especially if you force
them to log-on to your site prior to them being able to access your
site).

If you require any further assistance on this subject please do not
hesitate to ask for clarification.

Further information:
http://www.webmonkey.com//templates/print_template.htmlt?meta=/webmonkey/geektalk/96/41/index3a_meta.html
http://www.w3schools.com/asp/coll_servervariables.asp
http://www.lib.washington.edu/asp/browser/servar.asp
http://uk2.php.net/phpinfo
http://uk2.php.net/manual/en/reserved.variables.php

Thanks, that's exactly what I was looking for. Great work, thanks again =).

Thanks for the 5-star rating and tip!  They are both appreciated.