Citrix for Mac is an ICA Client specifically designed for OS X. It's used mainly by business that need extremely secure VPN connections. Note that Citrix for Mac has been replaced by a new plugin called Citrix Receiver but some users may prefer to stick with this standalone ICA client.
Citrix for Mac provides native connectivity to MetaFrame servers and features a slick Aqua user interface to blend-in with the overall look and feel of OS X. Citrix for Mac provides a useful alternative to using a SOCKS proxy and Citrix for Mac supports using a secure proxy with proxy authentication supported. Citrix for Client can automatically detect proxy server settings from the network settings in the client computer Network System Preferences. Citrix for Mac also provides support for Secure Sockets Layer 3.0 and Transport Layer Security 1.0.
Citrix for Mac is a slick native ICA Client for OS X.