On August 25, 1991, after five months of development, 21-year-old student Linus Torvalds announced in the comp.os.minix newsgroup the creation of a working prototype of the new operating system Linux, marking the completion of the porting of bash 1.08 and gcc 1.40. The first public release of the Linux kernel was presented on September 17. The kernel had a size of 62 KB when compressed and contained about 10,000 lines of source code. The modern Linux kernel comprises over 26 million lines of code. According to a study commissioned by the European Union in 2010, the approximate cost of developing a project equivalent to the modern Linux kernel from scratch would be US dollars (the calculation was made when the kernel had 13 million lines of code); according to estimates β .
The Linux kernel was created under the impression of the MINIX operating system, which Linus found unsatisfactory due to its restrictive license. Later, when Linux became a well-known project, detractors attempted to accuse Linus of directly copying code from certain MINIX subsystems. Andrew Tanenbaum, the author of MINIX, defended Linus, entrusting one of his students with conducting a detailed comparison of the code from MINIX and the first public versions of Linux. The research showed only four insignificant matches of code blocks, stemming from the requirements of POSIX and ANSI C.
Initially, Linus intended to name the kernel Freax, a combination of "free", "freak", and X (Unix). However, the name "Linux" was given to the kernel at the suggestion of Ari Lemmke, who, at Linus's request, placed the kernel on of the university, naming the archive directory not "freax", as Torvalds requested, but "linux". Interestingly, the entrepreneurial William Della Croce managed to register the trademark Linux and planned to collect royalties eventually, but later changed his mind and transferred all rights to the trademark to Linus. The official mascot of the Linux kernel, the penguin Tux, was chosen as a result of , held in 1996. The name Tux is an abbreviation for Torvalds UniX.
Growth dynamics of the code base (number of lines of source code) of the kernel:
- 0.0.1 β September 1991, 10 thousand lines of code;
- 1.0.0 β March 1994, 176 thousand lines of code;
- 1.2.0 β March 1995, 311 thousand lines of code;
- 2.0.0 β June 1996, 778 thousand lines of code;
- 2.2.0 β January 1999, 1.8 million lines of code;
- 2.4.0 β January 2001, 3.4 million lines of code;
- 2.6.0 β December 2003, 5.9 million lines of code;
- 2.6.28 β December 2008, 10.2 million lines of code;
- 2.6.35 β August 2010, 13.4 million lines of code;
- 3.0 β August 2011, 14.6 million lines of code.
- 3.5 β July 2012, 15.5 million lines of code.
- 3.10 β July 2013, 15.8 million lines of code;
- 3.16 β August 2014, 17.5 million lines of code;
- 4.1 β June 2015, 19.5 million lines of code;
- 4.7 β July 2016, 21.7 million lines of code;
- 4.12 β July 2017, 24.1 million lines of code;
- 4.18 β August 2018, 25.3 million lines of code.
- 5.2 β July 2019, 26.55 million lines of code.
Kernel Development Progress:
- Linux 0.0.1 β September 1991, the first public release, supporting only CPU i386 and booting from a floppy disk;
- Linux 0.12 β January 1992, the code began to be distributed under the GPLv2 license;
- Linux 0.95 β March 1992, support for launching the X Window System was provided, virtual memory and swap partition support were implemented.
- Linux 0.96-0.99 β 1992-1993, work on the network stack began. The Ext2 file system was introduced, ELF file format support was added, drivers for sound cards and SCSI controllers were introduced, and kernel module and /proc file system loading was implemented.
- In 1992, the first distributions SLS and Yggdrasil appeared. In the summer of 1993, the Slackware and Debian projects were founded.
- Linux 1.0 β March 1994, the first officially stable release;
- Linux 1.2 β March 1995, a significant increase in the number of drivers, support for Alpha, MIPS, and SPARC platforms, expansion of network stack capabilities, introduction of a packet filter, NFS support;
- Linux 2.0 β June 1996, support for multiprocessor systems;
- March 1997: LKML was founded, a mailing list for Linux kernel developers;
- 1998: the first Linux-based cluster made it to the Top500 list, consisting of 68 nodes with Alpha CPUs;
- Linux 2.2 β January 1999, increased efficiency of memory management system, added support for IPv6, implemented a new firewall, and introduced a new sound subsystem;
- Linux 2.4 β February 2001, support for 8-processor systems and 64GB of RAM, Ext3 file system, USB support, ACPI;
- Linux 2.6 β December 2003, support for SELinux, automatic kernel parameter tuning tools, sysfs, redesigned memory management system;
- In 2005, the Xen hypervisor was introduced, opening the era of virtualization;
- In September 2008, the first release of the Android platform, based on the Linux kernel, was formed;
- In July 2011, after 10 years of development in the 2.6.x branch. Transition to numbering 3.x. The number of objects in the Git repository has reached 2 million;
- In 2015, the release of the Linux kernel 4.0. The number of git objects in the repository reached 4 million;
- In April 2018 the milestone of 6 million git objects in the kernel repository.
- In January 2019, the kernel branch was formed. The repository reached 6.5 million git objects.
Source: opennet.ru
