All the software mentioned below (plus the underlying Linux operating system) is free software, in the full sense of the word: not just freely available for download from the internet (which it is), but more importantly, free for unrestricted use and ‘open source’. IE, it is ‘free’ as in free speech, not just ‘free’ as in free beer: we’re talking about freedom here, not price.
Free software means that you have the freedom to distribute copies of free software, that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things.
Most of the software is protected by a special kind of copyright licence, which guarantees its continuing freedom. Basically, the licence allows unrestricted use of the software, under the condition that it (and any derivative software) is distributed with the same ‘open source’ and free conditions. This license is often known as “copyleft,” because it is using copyright law itself to undermine the restrictive practices normally associated with copyright.
For more information, see the website of the Free Software Foundation, at http://www.uk.gnu.org/.
The underlying operating system and software that I use is Debian GNU/Linux, available from http://www.uk.debian.org/. See the website for more information on Debian, GNU software and Linux generally.
Linux is the free Unix written from scratch by Linus Torvalds with assistance from a loosely-knit team of hackers from across the Internet. Debian GNU/Linux is a particular distribution of the Linux operating system, and numerous packages that run on it.
Both Linux itself and the Debian distribution are developed using the open and distributed model, with hundreds of programmers contributing code across the internet. The code, together with lists of bugs, and developer and user mailing lists is all open and accessible over the web. This makes for better software, as well as freeing it from the commercial constraints that are inherent in proprietary programs.
The HTML files on this website are generated using the TeX4ht software, available from http://www.cis.ohio-state.edu/~gurari/TeX4ht/mn.html. This software works with Donald Knuth’s famous TEX typesetting software to generate HTML files. The manual for the software (see above link) has more details.
The particular TEX implementation that I use is teTeX, available from http://www.tug.org/tetex/.
If you are new to TEX (and curious), you may like to visit the TEX User Group website, at http://www.tug.org/, in particular at the FAQs (lists of ‘Frequently Asked Questions’, with answers) posted on that site. The UK-TUG FAQ, available from this FTP site is probably one of the best sources of general information. Because TeX4ht uses the TEX program itself to process the source TEX files, it is more robust, flexible and configurable than other tex-to-html converters.
I have included the source TEX files for each briefing on the website (accessible from the end of the briefing). I use PLAIN TEX. However, you will need copies of my own TEX macro files and the public macro packages eplain.tex, pdcfsel.tex and epsf.tex if you want to process the source files for the briefings. Please get in touch with me at andrew@andrewgray.uklinux.net for more information or if you want copies of my macro files.
The other software used to generate some of the files on this website is as follows:
•The ImageMagick suite of programs are used to generate any images used in the web pages. The ImageMagick programs are called automatically by TeX4ht, and are used to convert from DVI format (as output by TEX) to ‘portable network graphics’ (PNG) format. I have chosen to use PNG files rather than GIF files because of restrictive patents on the latter. ImageMagick is available from http://www.wizards.dupont.com/cristy/ImageMagick.html.
•The GNU ghostscript program is also used in the generation of images. GNU ghostscript is available from this FTP site.
•The flowcharts are written using xfig, a simple drawing program, and converted using its companion, transfig. Their home page is at http://www.xfig.org/.
•I use vim for editing the source text files that are used to create all the other files. Vim’s home page is at http://www.vim.org/.
•PDF versions of the briefings are generated using pdfTeX, available from http://www.tug.org/applications/pdftex/.