I chose 3 out of 5.Because there are some Os supported Windows Server 2003 Standard and Enterprise Editions with Service Pack 1 (client and server) ,Windows XP with Service Pack 2 (client),Netscape Navigator 7.2 (Windows),Mozilla 1.7 and 1.7.5 (Solaris and Windows) ,Java Plug-in 1.4.2_08 .