Everything.*
* Subject to your own understanding and skills.
The advantage to being able to modify Unix (or Linux, etc.) is that you can customize it to your liking, and in the case of Linux and its variants you can sell the changes. The disadvantage would be support; if you make a change you are responsible for fixing any problems that may develop.
Yes you can modify your computer but that will require very high level of skill to modify your operating system. If you are using Linux then it is easier to modify the way your computer runs.
Read this article, it shows you how to customize windows before you install it. http://www.goitexpert.com/entry.cfm?entry=Windows-Installation-Customization There is another one that shows you how to optimize Windows XP at; http://www.goitexpert.com/entry.cfm?entry=XP_Optimazation_Vol1
You can customize them online.
Linux Internals is a book about how Linux works.
Linux World is the Linux Development & Training Center
The courses available for Linux include Linux server, Linux desktop, bash shell, and many others.
you can customize batting gloves at rakmak.com
One can obtain the latest Linux news on websites such as CRN, Linux Today or Distro Watch. One can also find news about Linux on Arch Linux and Linux Journal.
No, it is unix-based but Linux is a kernel not an operating system.Ubuntu,Linux Mint,Debian,and puppy Linux,ect. are OS's that use the Linux kernel.
linux
Linux does not have a "manufacturer." Linux development is guided by the Linux Foundation and Linus Torvalds, with contributions from thousands of companies and individuals.