Out of curious!

I never used PDA to go online, that’s why I have this question. Is the I.E. in the PDA capible to read all web languages (Java, Javascript, Flash, XML & etc)? Coz years ago, it’s only capible reading HTML. If I wanted to, should I buy PDA with Palm OS or Windows OS? Which antivirus program is better to use? Appreciated any comments!!! Thanks!