What's new in Linux 2.6

A good article addressed the major improvements in Linux Kernel 2.6.xx, which have started to incorporate embedded support into Linux Kernel Main stream development.

What’s new in Linux Kernel 2.6.xxx
http://www.lynuxworks.com/products/whitepapers/linux-2.6.php3


SOME NOTES OF THIS ARTICLE
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Timeline:

November 2001: Start of 2.5.x development (2.4.15)
October 2002: Feature freeze for 2.6
Release of Linux 2.6.0: Dec-2003


USB 2.0 also makes its debut on Linux 2.6.
Version 2.6 integrates a significant portion of uClinux into the production kernel, bringing microcontroller support into the Linux mainstream.
Linux 2.6 introduces improvements that make it a far more worthy platform than in the past when responsiveness was an issue. The three most significant improvements are:
• Preemption points in the kernel
• An efficient scheduler
• Enhanced synchronization




SOME INTERESTING BACKGROUND INFO ABOUT LINUX TO READ
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Official Linux Kernel Release Web Site:
http://www.kernel.org/


Linux History:
http://en.wikipedia.org/wiki/Linux_history


Linux Kernel:
http://en.wikipedia.org/wiki/Linux_kernel

Estimated cost to redevelop
The cost to redevelop the Linux kernel version 2.6.0 in a traditional proprietary development setting has been estimated to be $612 million USD (€467 million euro) in 2004 prices using the COCOMO man-month estimation model.[55] In 2006, a study funded by the European Union put the redevelopment cost of kernel version 2.6.8 higher, at €882 million euro ($1.14 billion USD).[56]
This topic was revisited in October 2008 by Amanda McPherson, Brian Proffitt and Ron Hale-Evans. Using David A. Wheelers methodology, they estimated redevelopment of the 2.6.25 kernel now costs $1.3 billion (part of a total $10.8 billion to redevelop Fedora 9).[57] Again, Garcia-Garcia and Alonso de Magdaleno from University of Oviedo (Spain) estimate that the value annually added to kernel was about 100 million EUR between 2005 and 2007 and 225 million EUR in 2008, it would cost also more than one billion EUR (about 1.4 billion USD) to develop in European Union. [58]


There are many other well-known maintainers for the Linux kernel beside Torvalds such as Alan Cox and Marcelo Tosatti. Cox maintained version 2.2 of the kernel until it was discontinued at the end of 2003.
Likewise, Tosatti maintained version 2.4 of the kernel until the middle of 2006.
Andrew Morton steers the development and administration of the 2.6 kernel, which was released on 18 December 2003 in its first stable incarnation.
Also the older branches are still constantly improved.

• 25 January 1999 - Linux 2.2.0 was released (1,800,847 lines of code).
• 18 December 1999 - IBM mainframe patches for 2.2.13 were published, allowing Linux to be used on enterprise-class machines.
• 4 January 2001 - Linux 2.4.0 was released (3,377,902 lines of code).
• 17 December 2003 - Linux 2.6.0 was released (5,929,913 lines of code).
• 16 May 2010 - Linux 2.6.34 was released (13,320,934 lines of code).[16]