http://en.wikipedia.org/wiki/Linux_kernelOn 14 March 1994, Linux 1.0.0 was released, with 176,250 lines of code. In March 1995, Linux 1.2.0 was released (310,950 lines of code).
Version 2 of Linux, released on 9 June 1996, was followed by additional major versions under the version 2 header:
* 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).
* 24 December 2008 - Linux 2.6.28 was released (10,195,402 lines of code)