I am very impressed with FLDIGI in its latest iteration. It is the first digital mode program I have found that rivals, indeed may even exceed, MixW. Lots of folks like DM780 by Simon Brown, but I don't like the interface. Working FLDIGI is pretty simple and straightforward, like Skip Teller's wonderfully simple DigiPan, but it is loaded with the versatility of a multiplicity of modes only a mouse-click away -- very like MixW.
I had tried it with Linux in the past, but could never manage to interface properly with the rig. I am now auditioning it on Windoze Vista and it seems to work very well. I like that there is a gateway interface for DXKeeper -- my principal logger -- but it also works well as a stand-alone. Unlike MixW, FLDIGI will connect with that *other* site and swiftly look up a call and enter the data even before you save it to the log. That is a great help IMO.
If you like digital ops, I suggest giving it a try out (if you haven't already done so -- I am often among the those who never "got the memo" so to say). Not to be overlooked, it is FREE.