Re: Jam: which licence is this?

[Ricardo Wurmus <rekado@elephly.net>]

Vagrant Cascadian <vagrant@debian.org> writes:

> On 2021-04-25, Jack Hill wrote:
>> I'm working on packaging the Argyll Color Management System for 
>> Guix. To 
>> build, it uses the Jam tool, which has the following license:
>>
>> ```
>> This is Release 2.5 of Jam, a make-like program.
>>
>> License is hereby granted to use this software and distribute 
>> it
>> freely, as long as this copyright notice is retained and 
>> modifications
>> are clearly marked.
>>
>> ALL WARRANTIES ARE HEREBY DISCLAIMED.
>> ```
>
> Permission to use, check.
> Permission to study, probably(?)
> Permission to share, check.
> Permission to modify, .... ?
>
> Is it even free software? There is no mention of modification 
> which
> doesn't appear to be free by my layman's reading...
>
>
> Which brings up an ugly bag of worms regarding boost...

The jam build system in boost is also licensed under the Boost 
license:

The build system source is under tools/build/src/engine/, and the 
jam.cpp file has these notes:

--8<---------------cut here---------------start------------->8---
/*
 * /+\
 * +\   Copyright 1993-2002 Christopher Seiwald and Perforce 
 Software, Inc.
 * \+/
 *
 * This file is part of jam.
 *
 * License is hereby granted to use this software and distribute 
 it freely, as
 * long as this copyright notice is retained and modifications are 
 clearly
 * marked.
 *
 * ALL WARRANTIES ARE HEREBY DISCLAIMED.
 */

/* This file is ALSO:
 * Copyright 2001-2004 David Abrahams.
 * Copyright 2018 Rene Rivera
 * Distributed under the Boost Software License, Version 1.0.
 * (See accompanying file LICENSE_1_0.txt or copy at
 * http://www.boost.org/LICENSE_1_0.txt)
 */
--8<---------------cut here---------------end--------------->8---

FWIW I consider the Jam license to be free; it does mention 
modifications and only asks that they are “clearly marked” 
(whatever that means).  It’s much saner than the LaTeX license 
that asks that any modified file be renamed; it is only acceptable 
to the FSF license team because TeX has an aliasing mechanism, so 
it’s not a practical obstacle, merely a serious annoyance.

-- 
Ricardo