4.7. Future of the kernel and alternatives

At certain moments, advances in the Linux kernel were released at very short intervals, but now with a fairly stable situation regarding the kernels of the 2.6.x series, more and more time elapses between kernel versions, which in some ways is very positive. It allows time for correcting errors, seeing what ideas did not work well, and trying new ideas, which, if they work, are included.

In this section, we'll discuss some of the ideas of the latest kernels and some of those planned for the near future in the development of the kernel.

Example 4-12. Note

The kernel continues to evolve, incorporating the latest in hardware support and improved features.

The previous series, series 2.4.x [DBo], included in most current distributions, contributions were made in:

In the current series, kernel branch 2.6.x [Pra] has made important advances in relation to the previous one (with the different.x revisions of the 2.6 branch):

In the future, improvement of the following aspects is planned:

Example 4-13. Web site

POSIX specifications

www.UNIX-systems.org/

Also, although it is separate from the Linux systems, the FSF (Free Software Foundation) and its GNU project continue working on the project to finish a complete operating system. It is important to remember that the main objective of the GNU project was to obtain a free software UNIX clone and the GNU utilities are just the necessary software for the system. In 1991, when Linux managed to combine its kernel with some GNU utilities, the first step was taken towards the culmination in today's GNU/Linux systems. But the GNU project continues working on its idea to finish the complete system. Right now, they already have a core that can run its GNU utilities. This core is known as Hurd; and a system built with it known as GNU/Hurd. There are already some test distributions, specifically, a Debian GNU/Hurd.

Example 4-14. Web site

The GNU project:

http://www.gnu.org/gnu/ thegnuproject.html

Hurd was designed as a core for the GNU system around 1990 when its development started, since most of the GNU software had already been developed at the time, and the only thing that was missing was the kernel. It was in 1991 when Linus combined GNU with his Linux kernel that the history of GNU/Linux systems began. But Hurd continues to develop. The development ideas for Hurd are more complex, since Linux could be considered a conservative design, based on already known and implemented ideas.

Example 4-15. Reference

GNU and Linux, by RichardStallman: http://www.gnu.org/gnu/linux-and-gnu.html

Specifically, Hurd was conceived as a collection of servers implemented on a Mach microkernel [Vah96], which is a kernel design of the microkernel type (unlike Linux, which is of the monolithic type) developed by the University of Carnegie Mellon and subsequently by that of Utah. The basic idea was to model the functionalities of the UNIX kernel as servers that would be implemented on a basic Mach kernel. The development of Hurd was delayed while the design of the Mach was being finished and this was finally published as free software, which would allow its use for developing Hurd. At this point, we should mention the importance of Mach, since many operating systems are now based on ideas extracted from it; the most outstanding example is Apple's MacOS X.

The development of Hurd was further delayed due to its internal complexity, because it had several servers with different tasks of the multithread type (execution of multiple threads), and debugging was extremely difficult. But nowadays, the first production versions of GNU/Hurd are already available, as well as test versions of a GNU/Hurd distribution.

It could be that in the not too distant future GNU/Linux systems will coexist with GNU/Hurd, or even that the Linux kernel will be replaced with the Hurd kernel, if some lawsuits against Linux prosper (read the case of SCO against IBM), since it would represent a solution for avoiding later problems. In all events, both systems have a promising future ahead of them. Time will tell how the balance will tip.