KVM to IP via VNC

[Lister]

 Is there an open source solution for connecting to VNC KVM to
IP device(s) either stand alone or in tandem with other open
source product (e.g. ssh -L port:host:port, stunnel)?
 Is there an open source client that can scale down the screen
size of the remote host?
 Has anyone experience with any of these products :
http://www.lantronix.com/data-center-management/kvm-solutions/securelinx-slk.html
http://www.xceedium.com/html/products/Net_KVM.php
http://www.mycableshop.com/sku/SV1110IPEXT.htm

 TIA