Open Source and other Free Software

This is an annotated list of some open source or free software which I have found useful.

Operating Systems

Fedora Linux (I'm using Fedora 10) is one of several versions of Linux which can be downloaded from the Internet at no charge.  I have been using this for several years (since Fedora Core 1) and have had very few problems. 

For those who want a simple, compact and efficient Linux environment, Ubuntu is worth a look.  It comes with the Firefox browser, Evolution e-mail,  OpenOffice, and much more.

There are many other popular distributions of Linux as well, including openSuse and Knoppix.

If you need to run Linux programs under Windows, andLinux provides a version of Ubuntu running under the coLinux kernel.

Conversely, if you need to run Windows programs under Linux or Mac OS-X, try Wine.  It simulates every version of Windows from 3.1 to Vista, but not every program will run under Wine.  I use it mainly to run Google Sketchup on Linux.

File Search

Google Desktop Now that disk drives store hundreds or even thousands of gigabytes, it can be a challenge to find something you wrote last month or last year.  Google Desktop changes all that, and it's now available for Windows, Mac, and Linux.  Desktop will index all your files and e-mails so that you can locate items with any name or any content within seconds.

The Windows version also includes a toolbar with many handy widgets ("Gadgets"), but the Linux version just has a Quick Search Box which appears when a hotkey combination is pressed.  The default hotkey is Ctrl+Ctrl, meaning that you press the Ctrl key twice (sort of a double-click).  If necessary, you can easily change it to some combination of simultaneous key presses (such as Ctrl+`).

Google Desktop works best if you have a moderately fast machine (above 1 GHz) and plenty of free disk space to store the index files.  It takes a few hours to complete the initial indexing, but after that Desktop incrementally indexes your files.

Home Office Software

OpenOffice.orgOpen Office does word processing, spreadsheets, presentations and more.  I have used this for years, and find that its native files are very compact.  However, it can also read and write files compatible with other popular office programs (even the dread .docx format), and can output PDF files as well.  Available for Linux, Windows and Mac; a commercially supported and slightly fancier version for Windows and Linux is available as Star Office.

Web Page Design

KompoZerAfter using Mozilla Composer (now part of Mozilla Seamonkey) for several years, I am now using KompoZer which is a newer Mozilla-based tool.  KompoZer is available for Linux, Windows, and Mac.  If you can use a word processor, you can Kompozer.  It produces very clean HTML code that works with all browsers.

I don't recommend building web pages with Open Office (or worse yet with Microsoft Office) because the resulting HTML is difficult to maintain. 

There are many programs which automatically build photo galleries for the web.  I use Album from Dave's Marginal Hacks.  This is a Perl script which can be run under Unix, Linux, Windows, Mac, and probably other systems as well.

E-Mail Protection

Any e-mail address displayed in plain text on a web site is likely to start receiving "spam".  There are several ways to protect against that.  Although this site still uses Email Protector, I'm switching over to reCAPTCHA.  The idea in both cases is to encrypt the actual address, and reCAPTCHA adds a mini-Turing test to filter out bots.

Quality Control

Last but not least, web pages need quality control.  I use the free online W3C Markup Validation Service to check the HTML and the links on each page.  That avoids bad surprises, such as a page that works only with certain browsers.  Note however that the W3C link checker will flag Email Protector's encrypted links as invalid.  I've had no trouble with the links in practice, since the image file shows humans what address to use.


The GimpThe Gimp (GNU Image Manipulation Program) is a sophisticated program for drawing, editing, and transforming bitmap images; it is comparable to Adobe Photoshop Elements.  During the years I've used Gimp, it has constantly improved, with the addition of features such as forward and reverse perspective tranformations and increasingly powerful color adjustments.

When I wanted create a 3-D model of a now demolished Victorian house, POV-Ray was the answer.  Others have produced far more complex and realistic images, some of which can be seen on the POV-Ray home page.  Versions are available for Linux, Windows, and Mac.


If you need to solve systems of equations, invert matrices, integrate, differentiate, or run complex mathematical models, Octave or Maxima might be just what you need.  Octave resembles Matlab and is primarily directed at finding numerical solutions, while Maxima is more like Mathmatica, with strong symbolic math capabilities (though it will provide numerical solutions as well).  I've only recently begun to use these, but the possibilities look intriguing.  Octave is available for Linux, Windows, and Mac, while Maxima is available for Linux and Windows.  (Maxima is written in Common Lisp, so it should be readily portable to other architectures.)


Sky and Telescope magazine's web site has an extensive list of free, shareware, and open source software for astronomy.


Last updated May 16, 2009

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