There are lots of choices for using UNIX or at least some traditionally UNIX software at home or on a personal laptop.
Install Linux. Lots of departmental experience with dual booting Windows and Linux, esp. Fedora and Gentoo. Ask around, lots of people can help.
If you must use Windows, PuTTY is a free ssh client. It also has an scp program and an sftp program for secure copying and ftping. It does not need to be installed. Just download and run the executable. This is extremely highly recommended if you connect to other computers remotely from a Windows machine.
For Windows, check out Cygwin for GNU tools and X-Windows.
For Mac OS X (I know it is based on BSD, a UNIX, but it doesn't come with all of the useful standard UNIX stuff) there is Fink and Darwin ports. X11 and XCode are on the install CD and are very useful, but you must install them yourself (although the should be a default part of the OS, they aren't).
Astromake (by Peter Teuben) is a tool to load some software on your machine that are not installed by default. This includes PGPlot, a more recent version of Mozilla, the Intel Compilers, and several others. This is for GNU/Linux only.
To use, in your .tcshrc (bash users are on your own), include the
line:
source /astromake/astromake_start
Remember, unless unless you log out and then back in, you must type
source .tcshrc for changes to count. Then, to see what is available, type:
astroload -v
To actually load one of the programs type (or include in you .tcshrc
file) astroload followed by the name of the program you want.
OpenOffice is installed on the department computers. It is a free replacement for Microsoft Office. It can read and write Word, Excel, and Powerpoint files. At a command prompt, just type ooffice to start it.
We can break scripting up into two types: shell scripting and stand
alone scripting languages (Perl, Python, etc.). Many people in the
department use C Shell scripting, although bash is the more common
default shell on most computers these days (both Linux and OS X). C
shell scripting has a C like syntax and relies primarily on the use
of regular shell commands. Perl and python will be covered by other
people at a later date.
Shell scripting is just for very small jobs and for some configuration
files.
Some hints on shell scripting using tcsh and csh can be found here.
Several of the commonly used programs in the department are IDL, sm, PGPlot, and gnuplot.
This has far more features than any of the other plotting software listed here and can read and write tons of formats. This also makes it the hardest to use for quick little plots. It is big and expensive. If you use it, by far, the single best site about it is Coyote's Guide to IDL Programming. Don't bother with the printed manuals as they are hopelessly out of date (but the online ones which you get to by typing ? in IDL are okay).
This is popular in the department, so there are lots of people to talk to about it. Not free.
This is old school Fortran plotting. Great if you want control over every aspect of your plots and don't care about things like ease of use. If you actually want to use it, you probably want PGPerl. PGplot is used as the backend for programs like WIP, but some people (like me) use it with PGPerl for some of their plotting.
Octave is a free, partly Matlab compatible package which can provides an alternative (and somewhat more powerful) way to plot with gnuplot.
Gnuplot is simple, easy to script, free, but somewhat limited plotting
package. Good for quick plotting. It is one of the best packages for
3d surface plotting.
Go here for do a few
examples with gnuplot.