On a Cisco ASA, in the "Clientless SSL VPN" or "WebVPN", a TightVNC plug-in can be used.
http://www.cisco.com/en/US/docs/security/asa/asa80/configuration/guide/webvpn.html#wp1292902
This TightVNC Java plug-in does not support the UltraVNC "MS-Logon II" or the "New MS-Logon".
I installed UltraVNC 1.0.9.6.1 on a pc "MyVNCServer" and I downloaded the Java VncViewer via http://MyVNCServer:5800/VncViewer.jar/.
Can VncViewer.jar be used on a Cisco ASA as replacement fot the TightVNC java plug-in on a Cisco ASA?