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GPL 2.0 with FreeRTOS exception
GPL 2.0 with FreeRTOS exception
replaced by freertos-exception-2.0
The FreeRTOS source code is licensed by a modified GNU General Public License - the
modification taking the form of an exception.
The exception permits the source code of applications that use FreeRTOS solely
through the API published on this website to remain closed source, thus permitting
the use of FreeRTOS in commercial applications without necessitating that the whole
application be open sourced. The exception can only be used if you wish to combine
FreeRTOS with a proprietary product and you comply with the terms stated in the
The FreeRTOS download also includes demo application source code, some of which is
provided by third parties AND IS LICENSED SEPARATELY FROM FREERTOS.
For the avoidance of any doubt refer to the comment included at the top of each
source and header file for license and copyright information.
This is a list of files for which Real Time Engineers Ltd. is not the copyright owner
and are NOT COVERED BY THE GPL.
1. Various header files provided by silicon manufacturers and tool vendors that
define processor specific memory addresses and utility macros. Permission has been
granted by the various copyright holders for these files to be included in the
FreeRTOS download. Users must ensure license conditions are adhered to for any use
other than compilation of the FreeRTOS demo applications.
2. The uIP TCP/IP stack the copyright of which is held by Adam Dunkels. Users must
ensure the open source license conditions stated at the top of each uIP source file
is understood and adhered to.
3. The lwIP TCP/IP stack the copyright of which is held by the Swedish Institute of
Computer Science. Users must ensure the open source license conditions stated at the
top of each lwIP source file is understood and adhered to.
4. Various peripheral driver source files and binaries provided by silicon
manufacturers and tool vendors. Permission has been granted by the various copyright
holders for these files to be included in the FreeRTOS download. Users must ensure
license conditions are adhered to for any use other than compilation of the FreeRTOS
5. The files contained within FreeRTOS\Demo\WizNET_DEMO_TERN_186\tern_code, which are
slightly modified versions of code provided by and copyright to Tern Inc.
Errors and omissions should be reported to Richard Barry, contact details for whom
can be obtained from the Contact page.
This library is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software Foundation;
either version 2, or (at your option) any later version.
This library is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this
library; see the file COPYING. If not, write to the Free Software Foundation, 51
Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
GNU General Public License Exception
Any FreeRTOS source code, whether modified or in its original release form, or
whether in whole or in part, can only be distributed by you under the terms of the
GNU General Public License plus this exception. An independent module is a module
which is not derived from or based on FreeRTOS.
Linking FreeRTOS statically or dynamically with other modules is making a combined
work based on FreeRTOS. Thus, the terms and conditions of the GNU General Public
License cover the whole combination.
As a special exception, the copyright holder of FreeRTOS gives you permission to link
FreeRTOS with independent modules that communicate with FreeRTOS solely through the
FreeRTOS API interface, regardless of the license terms of these independent modules,
and to copy and distribute the resulting combined work under terms of your choice,
1. Every copy of the combined work is accompanied by a written statement that details
to the recipient the version of FreeRTOS used and an offer by yourself to provide the
FreeRTOS source code (including any modifications you may have made) should the
recipient request it.
2. The combined work is not itself an RTOS, scheduler, kernel or related product.
3. The independent modules add significant and primary functionality to FreeRTOS and
do not merely extend the existing functionality already present in FreeRTOS.
FreeRTOS may not be used for any competitive or comparative purpose, including the
publication of any form of run time or compile time metric, without the express
permission of Real Time Engineers Ltd. (this is the norm within the industry and is
intended to ensure information accuracy).