Virtualron
Virtual Iron had a nice product and the price was fair. I did an eval of virtualization products last year and VI was probably the best bang for the buck at the time (pre Citrix price changes) from a cost for features I wanted standpoint. I work for a SME and that is really where VI seemed to be putting their emphasis unlike VMware who seems to love the huge enterprise and not scale down so well.
Ultimately I decided that virtualization was too important to the company to place my faith in the hands of a startup that could easily go out of business or get bought. I'm feeling pretty good about that decision now.
I do find it funny that if you read many of the blog posting from VI's execs from late 2008 it was all VMware bashing. I guess they will have to change that. Actually I’m sure VMware will just fire the VI team since they are truly and completely redundant now. Hopefully a few of the better engineers will get picked up by Citrix or another XEN vendor.