Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
From the software concept called JeOS (pronounced "juice"), the Just Enough OS, to hardware concepts like Celio RedFly, an 8-inch screen and keyboard device running applications off a smartphone via a USB or a Bluetooth connection, there are an increasing number of indications that the center of gravity is shifting away from the traditional massive operating systems of the past.
Even the major OS vendors themselves are saying that the next versions of their OS -- Windows 7, Linux in its many distributions, and Mac OS X 10.6, aka Snow Leopard -- are getting a smaller footprint. Linux distribution vendors are also slimming down their versions of Linux. Ubuntu, for example, has stripped out MySQL, CUPS (Common Unix Printing Service), e-mail, and LDAP functionality to bring the size of its OS down from about 700MB to 200MB.
There are many reasons for the traditional OS to shrink and for new OSes to start small, but two stand out:
One, a smaller code base is easier to manage and secure than a large one. For example, estimates for Vista's development costs run around $6 billion, and BusinessWeek has estimated that 10,000 employees spent about five years developing it.
Two, a smaller OS can run on a greater variety of devices, and as netbooks, smartphones, and new devices such as the iPod Touch gain traction, the benefit of a smaller OS becomes hard to ignore.