Well, as you got here with a browser, I suggest the easiest way to download something is to first use your browser to go to the IBM page Browsers for AIX @ http://www-03.ibm.com/servers/aix/browsers/ (http://www-03.ibm.com/servers/aix/browsers/), and download the package of your choice Mozilla (which includes both browser and mail), or just Firefox.

After that, use ftp to upload the file to your AIX system. You may need zcat or bzip2 to unpack the file, and then use smitty install_latest to install the package.