A.2. FTP Sites
Although your Linux distribution provides precompiled binary packages for many Linux applications, often you need to build them from source code because the software is not available in binary form, you need to look at the source code, or you simply prefer to build it yourself from source. Here are some popular sites for the main sources of software that runs on Linux.
Many of these sites are extremely popular and busy. It is highly recommended that you use a mirror site (another computer system that downloads the software from the primary site on a regular basis) that is closer to you. A mirror site is usually easier to connect to and runs faster.
As well as the FTP sites listed here, many of the web sites listed in this Appendix Also have corresponding FTP sites for downloads.