COPYING

Coda is distributed under the terms of the GNU General Public License,
as shown in the file LICENSE.  Certain modules of Coda that may be useful
independently as libraries are distributed under the terms of the less
restrictive GNU Library General Public License, also shown in the file
LICENSE.lgpl.  The copyright notice at the beginning of each source file
indicates the applicable license.

Note that GPL and LGPL are copyrighted by the Free Software Foundation,
but the instances of the code they refer to in Coda is copyrighted by
Carnegie Mellon University and/or other technical contributors.

                        M. Satyanarayanan
                        School of Computer Science
                        Carnegie Mellon University
                        December 1998


Notes:

Our intent is that code which is a derivative work of this
distribution be covered by the GPL.  At the same time, we wish to
allow creation of proprietary system components that are written to
external interfaces in Coda so long as such proprietary code is
written independent of this distribution.  As explained below,
examples of such interfaces include the client-server RPC interface,
the kernel-Venus interface, and the ioctl interface used to Venus.

1. Each file will say what its license is. The libbase, LWP, RPC2 and
RVM subsystems come under the LGPL.  All files defining RPC
interfaces, such as those used by cache manager, volume utilities and
other utilities are LGPL'd.  This allows you, for example, to build a
proprietary cache manager using this interface. Most of these
interfaces are defined in the coda-src/vicedep directory.

2. The use of the kernel interfaces is considered ordinary use of the
system, so, for example, the ioctl's used in repair can be used by any
software not withstanding its license.  Similarly using the network
and kernel interfaces in the cache manager and file servers is
considered ordinary use of the system.  So, for example, it is
possible to write proprietary kernel code which uses those interfaces
when you port Coda to a new operating system.

3. A very limited number of files describe the interface between the
kernel and the cache manager, e.g. kernel-src/vfs/includes/coda.h.
This file is shared by the kernel code and the user level components
and you may distribute this file under the under the BSD-style license
included in that file in this distribution or the LGPL at your
discretion.

If you have questions, please contact us at coda@cs.cmu.edu.