About a year ago I've reached perfect solution and extremally cheap
multiuser environment for DOS application. It is GeorgiaSoftWorks
Telnet Server (3$ per seat and up to 400 users licence per server).
OS is Windows 2000 Professional. Disk operation on the computer are
relativelly slow and they have latency. But if you use SuperCache (199$)
on your system with lazywrite function enabled, then you can reach
incredible speed of programs, like under Netware or better. GSW allow
secure SSL session, reconnection after workstation crash, terminating
orphaned NTVDM, client side printig and more. There are GSW
(www.georgiasoftworks.com) and SuperCache (www.superspeed.com)
30 days trials enable. SuperCache is useful with every intensive disk
data mining products.

Regards,
Mariusz Adamowicz