> I don't understand this point: Isn't there just the LGPL to > ensure that
> gcc could be used for commercial applications?

Of course, but the LGPL does not apply to GPL'd libraries.  Regrettably, RMS and FSF are agitating against the use of LGPL these days, and many libraries are GPL'd but not LGPL'd, sometimes in part of out of ignorance, in part out of the lockstep following of the "movement's" dictates.  Indeed, FSF no longer refers to it as the "Library GPL," but as the "Lesser GPL."

See http://www.fsf.org/philosophy/license-list.html

> AFAIK the reason for LGPL is, that the standard libraries > necessary for
> ANSI-C are linked with the executables and shouldn't infect the user
> written program by a GPL license, because that would hinder gcc from
> widespread use. 

Entirely correct.

> With LGPL you only have to give the users of > the program
> the sources of the LGPL'd libraries if they want to have > them, but _not_
> the sources which you wrote outside these libs.

Entirely correct.

> And what's about the squeak VM: fileIO, printf() of messages > to stdout,
> etc.. It seems to be linked with a LGPL'd lib under Linux at least.

I believe, but I am not certain, that the GNU C Library is LGPL'd.

> First I've stumbled over the license (especially the Apple fonts
> problem), but now I also think that Squeak has a very good license:
> > It seems to be one of the best licences for
> - giving a free base system to all people without any fee,
> - ensure that improvements of the base system will flood back to the
> community,
> - enabling the use of squeak for commercial applications.

Agreed entirely.
 > The first point attracts many people which don't want to > spent money to
> make SWE (software engineering) as hobbyist. And sometimes > you make SWE
> without knowing if it ever brings money: The force to change the
> development platform then, if it smells a little bit after money,
> frightens people away to use it.
> > The last point pushes the development of Squeak very much 

Agreed.

> IMHO: The developers of commercial application will often > have the need for
> extending the base system to implement missing or new features, which
> are flowing back to the community; and on the other hand they are able
> to sell applications with clearly separated (from the base > system) parts
> and are able to earn money with it. So some commercially paid persons
> are in effect using a part of their working time to improve the base
> system for all! Isn't it nice!?

Quite.