I have been a fan of Linux for some time, and lately also of LJ, which I consider an excellent source of information. I have, however, been reluctant to address Linux as a target platform, because of the restrictions imposed by the GNU General Public License.

If I understand correctly, I may not compile a program with gcc under Linux and then expect to market it without accompanying source code. Also, I may not deny my licensee the right to re-distribute the program, or even sell it. This is because my application would constitute a “work based on gcc”, as defined in paragraph 1 of the GPL, and also because it would contain library code covered by the GPL.

But then, browsing through your magazine I found out that, for example, Caldera imposes much more restrictive terms on its products. Also, I have seen an ad about Mathematica for Linux, and I doubt that Wolfram Research is willing to qualify its product as a “work based on gcc”.

Clearly I am missing something. The question is, how can you market a commercial product under Linux and make sure that your customer is not re-selling it, or maybe installing it on 600 machines? Do you have to use a compiler other than gcc (is there any)?

I appreciate any advice you may give on the subject. Keep up the excellent work.

—Luca Cotta Ramusino lcotta@systemy.it

First of all, compiling with gcc does not make your application a “work based on gcc”. Second, the C library is not covered by the GPL, but by the LGPL, the GNU Library General Public License, which allows you to distribute applications linked to shared libraries without inheriting copyright restrictions. Third, there are at least two other C compilers available for Linux; Linux FT comes with a different compiler as the default system compiler, and lcc is also available.

So you can safely target Linux with your current GNU toolset.

Greetings. I read the January and February issues of LJ with great interest, especially the security section. In the February issue, you have the site for swatch as being sierra.stanford.edu:/pub/sources. It has moved to ftp.stanford.edu:/general/security-tools/swatch. I thought that this might be useful to anybody else who is looking for it...

Regards,

—Duncan Hill dhill@sunbeach.net

[The url he mentions has been corrected for this archive CD —Ed]