Re: ReRegarding iraf

[Glenn Maynard <glenn@zewt.org>]

On Mon, Jan 10, 2005 at 12:42:57PM -0500, Justin Pryzby wrote:
> > You can always link GPL material with non-GPL material, so long as that
> > other work is GPL-compatible.  
>
> What defines GPL compatibility?  Modify and distribute?

A license is GPL-compatible if it can be converted to the GPL.  In other
words, it can't apply any restrictions that the GPL does not, and it can't
prohibit the GPL's restrictions (eg. any other license with GPL#6's "may
not impose any further restrictions" is GPL-incompatible).

See

  http://www.gnu.org/philosophy/license-list.html

for a list of GPL-compatible and GPL-incompatible licenses, to get an idea
of which licenses the FSF considers incompatible and why.  (The FSF isn't
authoritative for applications of the GPL by others, but most follow their
judgement on this.)

-- 
Glenn Maynard