> <\body> One major objective of is to promote the development of free software for and by scientists, by significantly reducing the cost of producing high quality user interfaces. If you plan to write an interface between and other software, then please contact us. As a mathematician, I am deeply convinced that only free programs are acceptable from a scientific point of view. I see two main reasons for this: <\itemize> A result computed by a \Pmathematical\Q system, whose source code is not public, can not be accepted as part of a mathematical proof. Just as a mathematician should be able to build theorems on top of other theorems, it should be possible to freely modify and release algorithms of mathematical software. However, it is strange, and a shame, that the main mathematical programs which are currently being used are proprietary. The main reason for this is that mathematicians often do not consider programming as a full scientific activity. Consequently, the development of useful software is delegated to \Pengineers\Q and the resulting programs are used as black boxes. This subdivision of scientific activity is very artificial: it is often very important from a scientific point of view to know what there is in the black box. Inversely, deep scientific understanding usually leads to the production of better software. Consequently, I think that scientists should advocate the development of software as a full scientific activity, comparable to writing articles. Then it is clear too that such software should be diffused in a way which is compatible with the requirements of science: public availability, reproducibility and free usability. >