What tools have changed your Linux life? What were the most interesting commands, techniques or websites that have really helped you?

For me these were:

Webex
To share a desktop over the internet, even via proxies. Allows you to get and give support as well as training. However I first had to figure out how to use it with Linux, I described it here: http://www.linuxintro.org/wiki/Webex

scp
copies a file over the network from one Linux computer to another Linux computer. Syntax is:
scp file user@remotehost:/path

strace
helps you to find what a process does and where it passes most of its time. I blogged about it

Send a program to the background
How often have you started a program in a shell and then wanted to start the next program with the current program still running? The solution is to send the program to the background:

• stop it with the key combination CTRL_Z
• resume it in the background with the command
  bg

shellinabox
You'll have a website with a Linux shell on it. I describe it here: http://www.linuxintro.org/wiki/Shell_in_a_box

guacamole
You'll have a website with a Linux desktop in it. I describe it here: http://www.linuxintro.org/wiki/Guacamole. No browser plugin needed!

Emacs - Why should each thing have a cruddy UI / half-bake text editor for forms and fields.... When you can have an full featured text editor that can drive anything?

Ruby (or D) - Script your life.


Mercurial - Archive your life.

bash/sh - I can hack up a program to do nearly anything in bash, if not I can use C for part or all of it.

lftp - very useful for automated updates

cryptsetup/dm-crypt - very powerful and useful encryption

gnupg - can also be used for encryption, but I mostly use it for verification and hashes

Xdialog - great add-on to make bash scripts even more powerful and useful

geany - great IDE and text editor

Bash - number 1 on my list

ssh/scp

cryptsetup

vlc/ffmpeg/mplayer/mencoder/handbrake - my most widely used video/audio editing/playing tools

tovid - dvd authoring

http://www.commandlinefu.com - great website to pick up command line tasks

And many more. Too much to list here.

bash, ssh, emacs, etc.

One of the big ones lately though has been VirtualBox. I deal a lot with software/hardware that requires a custom environment. Either a piece of hardware that requires a certain toolchain to use, or a piece of software that requires a certain distro, etc. Or even special tools that I want to isolate to a VM for portability, security, etc. (eg: DNS server, DHCP server, FTP server...)

Rather than hack up my main system I typically just set up a VM for it, assign it ~2 GB of RAM, start it up in headless mode on boot, and then never think about it again. If something happens to the host machine, I just transfer the VM over to another box, register it, and boot it up like normal.

One of the nice things about running a Linux guest on a Linux host through VirtualBox is it only uses the RAM that's actually being used by the guest, regardless of the amount you assign it. So you can assign a guest 2 GB but if it just sits there headless with no GUI, the actual RAM usage on your main machine might be only 200 MB, which can let you run tons of VMs at the same time with only a modest machine.

Plus you have snapshots, easy full backups, etc.

sshfs
wget/curl
mc (I was not a Norton Commander user, and mc found me first)
vim/gvim
mplayer

TigerVNC is likely to be added to the list soon.

Thanks for sharing! I am taking notes as much as I can. lol

As a windows newbie, I would vote for the command below.
nautilus .
I just cannot do anything without it in the shell under GNOME. Once the file manager/explorer pops out, I feel like I am powerful again! >_<