Last updated 8-12-2022,
Note that I will be letting my domain, http://www.multi-seat.com/ expire on October 10, 2022. This content will continue to be available from the “Multi-Seat” menu item of my other domain, http://raspiplayer.com/
Multi-seat is a generic term that refers to an operating system capable of, and configured for, supporting multiple workstations per computer. It is usually associated with the Linux operating system since Microsoft Server has a proprietary name for this functionality, as do other proprietary systems that build on top of Microsoft Server such as nComputing’s, and the proprietary version of Linux called Userful Multiplier.
Advantages of multi-seat are centralization of administration, security, load sharing, and energy efficiency. Most of the time a computer is idling while waiting for you to type or move the mouse. With multiple workstations connected, the computer supporting these workstations can be productive for a larger percentage of the time. It doesn’t have to be n times more powerful than a standalone computer because the individual workstations don’t all require simultaneous cpu support. Modern computers are much faster than a single user can utilize just accessing a library catalog, browsing the web, or running office and multimedia editing software.
The term multi-seat (also spelled multiseat) does not specify whether the hardware driving the displays resides in the server computer with video cables connecting the displays, or as a USB or network attached zero client. Network attached zero clients utilize a special chip designed and manufactured by Elite Silicon Technologies which translates USB protocol to network protocol in hardware at the zero client end (without a cpu) which the server computer translates back to USB using proprietary algorithms so that the USB 2.0 max cable length of 5 meters can be extended to the cat 5E max cable length of 100 meters.
Before zeroclients, there were thinclients (and sometimes fat clients depending on whether the apps ran on the server or the thinclient). The free Edubuntu linux distribution contained a thinclient server. Their thinclients ran a pared-down Edubuntu OS whose only function was to boot over the network from the server, display content on the display sent to it by the server, and to return key strokes and mouse events back to the server. Older, slower computers were frequently repurposed for these thinclients. If they were fast enough to run some apps locally, they were called fat clients.
The largest multi-seat installation was 523,400 Stations in 45,000 schools for Brazilian Ministry of Education by 2010.
This installation involved the free Edubuntu Linux OS with paid extensions for multi-seat licensed from a B.C. Canadian company utilizing special internal PCI video cards manufactured in Brazil that provided several completely independent video outputs per PCI slot.
When the Brazilian Ministry of Education ran into conflicts with the supplier of these internal video cards over updated drivers to support more recent versions of Linux and Userful started requiring an annual maintenance subscription in addition to the original license for their multi-seat extensions, Brazil started producing their Linux educational OS internally. The branding logo of my webpage shows login screens on three workstations connected to three HP zero clients and running LE 6.1.0 developed by the government of Brazil for their public schools and universities which I have reconfigured for English since I don’t speak Portuguese. https://linuxeducacional.c3sl.ufpr.br/instalacao/
For a recent historical analysis of the Brazilian adaptation to digital resources in education, see: https://files.eric.ed.gov/fulltext/EJ1261764.pdf
The last release of Edubuntu Linux was 2014 and the project has been discontinued. It was based on thin clients and was the most widely used free system in the USA for schools. Globally, Skol Linux/Debian Edu had the most educational installations, is current, and was also based on thinclients. https://wiki.debian.org/DebianEdu/
There have been major changes in hardware technology and market forces. One important factor has been the adoption of cell phones. To give useful numbers of hours between charging, they needed energy efficient new cpu, and it was desirable that their internal computers be very compact. Microsoft failed to dominate this market, so there has been more competition and more innovation. Intel and AMD also failed to dominate this market with the same failure to stifle competitors. The scale of manufacture for cell phones has allowed these new technologies to spill over into Chromebooks, tablets and Android smart TV boxes based on the armhf cpu. The Android OS is an attempt to make endusers and software developers pay license fees. Android is a layer of software that runs on top of the free Linux OS.
Another impact is the not for profit, https://www.raspberrypi.org/ To teach students computer programming, they manufacture their own small board computers. This manufacture is also not for profit. Under my X2GO sub page, I show how you can save over $100/networked zero client by installing the free x2go on a Raspberry Pi 4B. http://www.multi-seat.com/x2go/
But why still use Intel and AMD cpu for the server computer when the Pi 4B and similar Android TV boxes can be repurposed with Linux by moving more of the computing work to the client to reduce the load on the server. See my PiServer sub page for centralizing administration, authentication of users, and file storage. http://www.multi-seat.com/piserver/ Piserver is a good platform for controlling pi client network connected displays in digital signage. See my RaspiPlayer sub page here, or directly from http://raspiplayer.com/
If you are buying new hardware, the Raspberry Pi 4B is most cost effective. If you already own USB or network attached zero clients, see my Legacy and its sub pages for documentation as well as my store of surplus hardware for sale. http://www.multi-seat.com/legacy/