Subject: [SWIPL] XPCE/Prolog now OpenSource

From: Jan Wielemaker <[email-masked]>
Date: Thu, 1 Feb 2001 10:50:18 +0100

Hi,

Yesterday we've decided to change the license conditions of the XPCE GUI
toolkit for (SWI-)Prolog to OpenSource (GPL).

Some work needs to be done to put the proper license-term references in
the right place, update web and documentation and provide download and
CVS facilities similar to SWI-Prolog.

For now, the Windows executable on the XPCE download page no longer
checks for a license code and doesn't stop working after 20 minutes.

Plans
=====

We plan to make two releases of SWI-Prolog in the future. The `standard'
build will contain the SWI-Prolog kernel and a selection of the
packages. Probably this will be XPCE, the SGML tools, C++ interface, the
static tabling package, the `clib' package (only partly on Windows) and
the GUI tracer.

The sources of the packages will be combined and completed with an
overall build-script, though the packages remain independent pieces
of software only using the defined foreign interfaces to communicate.

Next there will be SWI-Prolog/lite, which is a continuation of the
current release.

When all this is finished it will be called SWI-Prolog 4.0

License summary
===============

The entire package will be distributed under the GPL, some of the
packages under the LGPL. Very briefly and (over-)simplified, this
implies you can do whatever you like as long as you provide the complete
source code with whatever executables you distribute.

For (XPCE)/Prolog applications this implies you must distribute them as
source or at least provide the source or a pointer where users can
freely acquire the source.  If you do not wish to distribute source
to your clients you must buy a commercial license.  As soon as the
package is ready we will decide on commercial packaging and pricing.

Old licenses and `Thanks'
=========================

Holders of commercial SWI-Prolog and XPCE licenses won't notice the
change. Holders of academic licenses keep their license, though in
practice this license is replaced by the GPL which in almost all areas
provides more rights.

We are grateful to the buyers of academic licenses over the past years.
They helped a lot making XPCE possible. We believe the new schema will
help XPCE grow and commercial licenses will fill the gap. 

	Regards --- Jan