The History of Thin Clients
A thin client (also called zero client, slim clientor cloud client) is a computer or a computer program that depends heavily on another computer (its server) to fulfill its computational roles. This is different from the traditional fat client, which is a computer designed to take on these roles by itself.
Thin clients have their roots in multi-user systems, traditionally mainframes accessed by some sort of terminal computer. As computer graphics matured, these terminals transitioned from providing a command-line interface to a full graphical user interface. This is more common on modern advanced thin clients. The prototypical multiuser environment along these lines, Unix, began to support fully graphical X terminals, i.e., devices running display server software, from about 1984. X terminals remained relatively popular even after the arrival of other thin clients in the mid-late 1990s. Modern Unix derivatives like BSD and GNU/Linux continue the tradition of the multi-user, remote display/input session. Typically, X software is not made available on non-X-based thin clients, although no technical reason for this exclusion would prevent it.
Windows NT became capable of multi-user operations primarily through the efforts of Citrix Systems, which repackaged NT 3.5.1 as the multi-user operating system WinFrame in 1995. Microsoft licensed this technology back from Citrix and implemented it into Windows NT 4.0 Terminal Server Edition, under a project codenamed ‘Hydra’. Windows NT then became the basis of Windows 2000 and Windows XP. As of 2011 Microsoft Windows systems support graphical terminals via the Remote Desktop Services component.
The term thin client was coined in 1993 by Tim Negris, VP of Server Marketing at Oracle Corp., while working with company founder Larry Ellison on the launch ofOracle 7. At the time, Oracle wished to differentiate their server oriented software from Microsoft’s desktop oriented products. Ellison subsequently popularized Negris’ buzzword with frequent use in his speeches and interviews about Oracle products.
The term stuck for several reasons. The earlier term ‘graphical terminal’ had been chosen to distinguish such terminals from text-based terminals, and thus put the emphasis heavily on graphics – which became obsolete as a distinguishing characteristic in the 1990s as text-only physical terminals themselves became obsolete, and text-only computer systems (a few of which existed in the 1980s) were no longer manufactured. The term ‘thin client’ also conveys better what was then viewed as the fundamental difference: thin clients can be designed with less expensive hardware, because they have reduced computational workloads.
By the 2010s, however, thin clients were not the only desktop devices for general purpose computing that were ‘thin’ – in the sense of having a small form factor and being relatively inexpensive. The Nettop form factor for desktop PCs was introduced, and nettops could run full feature Windows or Linux; tablets and tablet-laptop hybrids had also entered the market. However, while there was now little size difference, thin clients retained some key advantages over these competitors, such as not needing a local drive. However, ‘thin client’ can be a misnomer for slim form factor computers using flash memory such as compactflash, SD card, or permanent flash memory as a hard disc substitute.