Linux Programming Hints

Hopefully you have an understanding of the ideas behind the Free Software Foundation and the GNU project from What's GNU? in LJ #1. Some libraries required a different sort of free license from other copylefted code.

Remember, the goal is to make sure that developers who use copylefted code don't restrict the end user's rights. But, if developers included code covered by the General Public License in their products it would mean that they would have to make the source code of their own products available.

To support the end user without hampering the proprietary rights of the developer, the GLPL was created. It allows developers to use these free libraries with their products without having to release their source code. Although the legalese is more complicated, the basics are that the developers must either:

make a linkable form of their programs available so the user can re-link with newer libraries; or
use dynamic libraries so the actual library code is not included in the productjust the linkage to the library.

Linux supports dynamic linking (which has the additional advantage of making executable programs much smaller), so this is generally the approach taken by people developing applications for Linux.

The full text of the GNU Library Public License is available from ftp sites or from the Free Software Foundation.