I am looking at network-attached USB hubs in order to run licensed software in a virtualized environment when hardware dongles are required.
Are there any solutions that will work with both Linux and Windows? Most of the dedicated devices -- such as the Zonet ZUH2214 or the (oddly expensive) Digi AnywherUSB/2 -- appear to be Windows-only. Linux has the the USB/IP project, for which there appear to be Windows drivers, but the last "News" post on the site was in 2007, so I'm not entirely confident about the viability of the project.
Has anyone out there found a solution that will work well in both environments?
Maybe this is a longshot, but with the prevalence of fully virtualized environments, some software vendors have had to modify their licensing schemes to accommodate clients. I recently ran into this situation with a USB dongle needed to authorize the use of a financial analysis package. I called the software manufacturer and they were able to provide an alternative licensing mechanism specially intended for virtualized setups. It's worth a try.
The USB-IP Project mentioned in the question actually has had updates all the way through June 2011, when the current version of the Windows driver was released. If you are looking for a cross-platform solution, this is the only option that I am aware of.
You might try getting into fabulatech's beta for the linux client. DUAL OS support is suppossedly coming soon. Note that hardware dongles are notoriously finicky, and all of these solutions require additonal drivers in the VM. additionally the dongle may not support usb over IP at all