Use actual planned license header (GPL, FLOSS exception, alternative available)

Add floss exception doc

doc/FLOSS-exception.txt

+Linden Research, Inc. ("Linden Lab") Viewer FLOSS License Exception v0.5
+
+The Linden Lab Exception for Free/Libre and Open Source Software-only
+Applications Using Linden Lab Viewer Software (the "FLOSS Exception").
+
+Exception Intent
+
+Linden Lab is releasing the source code for certain software that
+enables users to view or otherwise access the Second Life virtual
+world environment (the "Viewer Software"), under version 2 of the GNU
+General Public License (the "GPL").  The creation or distribution of
+works based on the Program (as defined under the GPL) of the Viewer
+Software may require the use of certain Free/Libre and Open Source
+Software ("FLOSS") works that are subject to license agreements not
+compatible with re-licensing under the GPL.  Because we want to allow
+the Viewer Software to be distributed with these FLOSS works, this
+FLOSS Exception following exception applies subject to the terms and
+conditions below.
+
+Legal Terms and Conditions
+
+As a special exception to the terms and conditions of version 2.0 of
+the GPL:
+
+You are free to distribute a work based on the Program that is formed
+entirely from the Viewer Software (and any modifications thereof) and
+one or more works that are independent and separate works not derived
+from the Viewer Software, and are licensed under one or more of the
+licenses listed below in section 1 (each, a "FLOSS Work") , as long
+as:
+
+   A. You obey the GPL in all respects for the Viewer Software and any
+      work based on the Program, except for the FLOSS Works, for which
+      you must comply with B below,
+
+   B. all FLOSS Works,
+
+         i.  are distributed subject to one of the FLOSS licenses
+             listed below, and
+
+         ii. the object code or executable form of the FLOSS Works are
+             accompanied by the complete corresponding
+             machine-readable source code for those FLOSS Works on the
+             same medium and under the same FLOSS license as the
+             corresponding object code or executable forms thereof,
+             and
+
+   C. any works that are aggregated with the Viewer Software or a work
+      based on the Program on a volume of a storage or distribution
+      medium in accordance with the GPL, and are not licensed under
+      the FLOSS licenses listed below, are independent and separate
+      works in themselves which are not derivatives of either the
+      Viewer Software, a work based on the Program or a FLOSS Work.
+
+If the above conditions are not met, then the Viewer Software may only
+be copied, modified, distributed or used under the terms and
+conditions of the GPL or another valid licensing option from Linden
+Lab.
+
+1. FLOSS License List
+
+License name                                Version(s)/Copyright Date
+Academic Free License                                             2.0
+Apache Software License                                   1.0/1.1/2.0
+Apple Public Source License                                       2.0
+Artistic license                                      From Perl 5.8.0
+BSD license                                            "July 22 1999"
+Common Development and 
+    Distribution License (CDDL)                                   1.0
+Common Public License                                             1.0
+GNU Library or "Lesser" General 
+    Public License (LGPL)                                     2.0/2.1
+Jabber Open Source License                                        1.0
+MIT License (As listed in file MIT-License.txt)                     -
+Mozilla Public License (MPL)                                  1.0/1.1
+Open Software License                                             2.0
+OpenSSL license (with 
+    original SSLeay license)                          "2003" ("1998")
+PHP License                                                       3.0
+Python license (CNRI Python License)                                -
+Python Software Foundation License                              2.1.1
+Sleepycat License                                              "1999"
+W3C License                                                    "2001"
+X11 License                                                    "2001"
+Zlib/libpng License                                                 -
+Zope Public License                                               2.0
+
+Due to the many variants of some of the above licenses, we require
+that any variant of the above licenses be identical in substance to
+the form approved by the Open Source Initiative and follow the 2003
+version of the Free Software Foundation's Free Software Definition
+(http://www.gnu.org/philosophy/free-sw.html) or version 1.9 of the
+Open Source Definition by the Open Source Initiative
+(http://www.opensource.org/docs/definition.php).
+
+2. Definitions
+
+Terms used, but not defined, herein shall have the meaning provided in
+the GPL.
+
+3. Applicability
+
+This FLOSS Exception applies to all Viewer Software files that contain
+a notice placed by Linden Lab saying that the Viewer Software may be
+distributed under the terms of this FLOSS Exception. If you create or
+distribute a work which is a work based on the Program for the Viewer
+Software and any other work licensed under the GPL, then this FLOSS
+Exception is not available for that work; thus, you must remove the
+FLOSS Exception notice from that work and comply with the GPL in all
+respects, including by retaining all GPL notices. You may choose to
+redistribute a copy of the Viewer Software exclusively under the terms
+of the GPL by removing the FLOSS Exception notice from that copy of
+the Viewer Software, provided that the copy has never been modified by
+you or any third party.