Highly recommended. Gri is a FREE graphics language that is straightforward, relatively easy to learn, and produces pretty pictures like this one and this one. Can be installed on Windows or *nix machines. Uses commands like "read columns" and "draw curve". My kind of programming!
The Grid Analysis and Display System (GrADS)
For high-quality output and large datasets, GrADS is the way to go. Here are some tips and tricks I have learned over the years. More to be added as I get time and remember the tricks myself. My live weather page uses GrADS for the model images.
A super little text editor for Windows machines. Should replace everyone's Wordpad (*yuck*) or Notepad (*yawn*).
I use LaTEX for most journal article submissions (example), when writing homeworks and exams, and anything else that I want to distribute that "looks formal." The learning curve is kinda steep, but the peak is far higher than anything you could ever do with a Microsoft product orOpenOffice. For example, I keep a master reference list in AGU format. To change the entire file to AMS format, I need only alter one single line of code. Keep that in mind next time you're editing references at the back of a document. Also available: a thesis/dissertation template for use at UAHuntsville. Documents are cross-platform portable. I use a *nix version at work, a version through Cygwin on my home machine, and a Windows-compatible version (MiKTEX) on my laptop. If you do a Google search for LaTEX, make sure that when you do it, you are searching for web links, NOT images. (LaTEX = latex. Careful.)
Others
To view real time surface and upper air data at home, Digital Atmosphere. Their newer releases ($$$) handle just about every type of data imaginable.
An archived Level II radar viewer from Gibson Ridge Software.
When I write code, I prefer to do it in Fortran. Usually, those programs have a front end written in Perl to do any text editing.
Also important to me is being able to transport code across platforms--so my home machines (XP) are equipped with Cygwin and well-stocked with compilers/programming languages (g77, C/C++, Active Perl, and others).