All of you may know about the top command line of linux, well there are a lot of similar programs to monitor other type of resources, here we have some of the more useful to me,

iftop
This is a nice one to monitor network usage, more specific bandwidth usage.

Installation:

cd /usr/local/src
wget http://www.ex-parrot.com/~pdw/iftop/download/iftop-0.17pre3.tar.gz
tar -xvzf iftop-0.17pre3.tar.gz
cd iftop-0.17pre3
./configure && make && make install

You wil need libcap and libcurses but most of the cases they are already installed.

mytop

This program can be quite useful to debug mysql.

Installation:

Install TermReadKey,

cd /usr/local/src
wget http://search.cpan.org/CPAN/authors/id/J/JS/JSTOWE/TermReadKey-2.30.tar.gz
tar -xvzf TermReadKey-2.30.tar.gz
cd TermRead*
perl Makefile.PL
make test && make && make install

Install DBI,

cd /usr/local/src
wget http://search.cpan.org/CPAN/authors/id/T/TI/TIMB/DBI-1.48.tar.gz
tar -xvzf DBI-1.48.tar.gz
cd DBI*
perl Makefile.PL
make test && make && make install

Now finally mytop,

cd /usr/local/src
wget http://jeremy.zawodny.com/mysql/mytop/mytop-1.4.tar.gz
tar -xvzf mytop-1.4.tar.gz
cd mytop*
perl Makefile.PL
make test && make && make install

apachetop

This is a program that uses the logs of apache to monitor it.

Installation:

cd /usr/local/src
wget http://www.webta.org/apachetop/apachetop-0.12.6.tar.gz
tar -xvzf apachetop-0.12.6.tar.gz
cd apachetop-0.12.6
./configure && make && make install