In this unit's limited space we cannot comment on all the tools that can offer us benefits for administration. We will cite some of the tools that we could consider basic:
The various basic UNIX commands: grep, awk, sed, find, diff, gzip, bzip2, cut, sort, df, du, cat, more, file, which...
The editors, essential for any editing task, like: vi, very much used for administration tasks because of the speed of making small changes to the files. Vim is the vi compatible editor, which GNU/Linux tends to carry; it allows a syntax coloured in various languages. Emacs, a very complete editor, adapted to different programming languages (syntax and editing modes); it has a very complete environment and an X version called Xemacs. Joe, editor compatible with Wordstar. And many more...
Scripting languages, tools for administration, like: Perl, very useful for handling regular expressions and analysing files (filtering, ordering etc.). PHP, language that is very often used in web environments. Python, another language that can make fast prototypes of applications...
Tool for compiling and debugging high level languages: GNU gcc (compiler of C and C++), gdb (debugger), xxgdb (X interface for gdb), ddd (debugger for various languages).