Our multiseats are using only free and open source software. With one mouse click it is possible to update the complete system, including installed programs,  so you are always using  the most recent software. Ubuntu 9.04 or Debian 5 are used (always the last version).

Windows is technically not able to work in multiseat . There are  windows multiseat products available  which uses software- virtualisation. These systems work only with the out-of-date windows Xp, where the support is omitted in some months. Ofcourse with Windows you cannot work 'virus free'. With Windows multiseat (and also windows thin client systems)  a license  is necessary of windows XP and other  Microsoft programs(such as Office) for every user. These Windows multiseat systems only allows software to be installed that has been certified by these companies.So own software programs installations are not possible. Performance with Windows Xp (and later versions) is always proven to be slowing down the computer after some months, these happens faster with Windows multiseat. Windows Xp pro manage only 4 gb ram, therefore with a six-seat configuration there is only  666mb ram per user, this is insufficient for modern software.

Multi-user systems windows/ubuntu licenses comparison:

Ncomputing(thin client sytem)	Betwin(closed software multiseat)	SoftXpand(closed software multiseat)	Ubuntu Multiseat(opensource)
windows server license+CAL's per user + commercial software license per user	Betwin license:86eur per user + windows xp license per user + commercial software license per user	SoftXpand license:92eur per user + windows xp license per user + commercial software license per user	None