Linux

X Window System (X11) is the windowing system for bitmap display, common on UNIX-like OSes. X provides the basic framework for a GUI environment. It does not mandate the user interface - this is handled by individual programs, such as window managers. A window manager controls the placement and appearance of application windows. Examples of window managers include GNOME 2, KDE and Awesome.

Mount DVD drive in Ubuntu

mount /dev/cdrom [dir]

In my case, I mount it in the existing media directory.

Video and audio conversion

For video conversion, avidemux is a good tool. Today I used it to rotate a mp4 video by 180 degrees. The instructions can be found here.

For audio conversion, soundconverter is good. I used it to convert a wma file to mp3. The instructions can be found here.

Adding printers at CSAIL on Ubuntu

1. Go to Printing and click "Add".
2. Under Network Printer, choose LPD/LPR Host or Printer.
Host: cups.csail.mit.edu
Queue: [Printer Queue Name] (i.e. xerox2)
3. Choose the option to provide the driver yourself. You can download the driver here.

Command to remove all .svn folders

find ./ -name ".svn" | xargs rm -Rf

Explanations:
xargs is used to build and execute command lines from standard input. It breaks list of arguments into sublists small enough to be acceptable.