Anybody still using IBM Mainframe APPS such as TSO, CICS, IMS or any of the apps running under these -- You probably are still using Windows pacakges to provide IBM terminal emulation.
No problem under Linux as the 3270 package comes with the distrobution and is easy to connect
Much cheape than using rubbish corporate packages such as ATTACHMATE.
Here's a Linux screen shot of a TSO application and an IBM mainframe console running on Linux (SUSE 9.1 Pro)
http://www.1kyle.com/ibm.jpg