Asterisk is distributed under the GNU General Public License version 2
and is also available under alternative licenses negotiated directly
with Digium, Inc. If you obtained Asterisk under the GPL, then the GPL
applies to all loadable Asterisk modules used on your system as well,
except as defined below. The GPL (version 2) is included in this
source tree in the file COPYING.
This package also includes various components that are not part of
Asterisk itself; these components are in the 'contrib' directory
and its subdirectories. These components are also distributed under the
GPL version 2 as well.
Digium, Inc. (formerly Linux Support Services) holds copyright
and/or sufficient licenses to all components of the Asterisk
package, and therefore can grant, at its sole discretion, the ability
for companies, individuals, or organizations to create proprietary or
Open Source (even if not GPL) modules which may be dynamically linked at
runtime with the portions of Asterisk which fall under our
copyright/license umbrella, or are distributed under more flexible
licenses than GPL.
If you wish to use our code in other GPL programs, don't worry --
there is no requirement that you provide the same exception in your
GPL'd products (although if you've written a module for Asterisk we
would strongly encourage you to make the same exception that we do).
Specific permission is also granted to link Asterisk with OpenSSL, OpenH323
UniMRCP, and/or the UW IMAP Toolkit and distribute the resulting binary files.
In addition, Asterisk implements several management/control protocols.
This includes the Asterisk Manager Interface (AMI), the Asterisk Gateway
Interface (AGI), and the Asterisk REST Interface (ARI). It is our belief
that applications using these protocols to manage or control an Asterisk
instance do not have to be licensed under the GPL or a compatible license,
as we believe these protocols do not create a 'derivative work' as referred
to in the GPL. However, should any court or other judiciary body find that
these protocols do fall under the terms of the GPL, then we hereby grant you a
license to use these protocols in combination with Asterisk in external
applications licensed under any license you wish.
The 'Asterisk' name and logos are trademarks owned by Digium, Inc.,
and use of them is subject to our trademark licensing policies. If you
wish to use these trademarks for purposes other than simple
redistribution of Asterisk source code obtained from Digium, you
should contact our licensing department to determine the necessary
steps you must take. For more information on this policy, please read:
If you have any questions regarding our licensing policy, please
+1.877.344.4861 (via telephone in the USA)
+1.256.428.6000 (via telephone outside the USA)
+1.256.864.0464 (via FAX inside or outside the USA)
IAX2/pbx.digium.com (via IAX2)
email@example.com (via email)
445 Jan Davis Drive
Huntsville, AL 35806