FreeRTOS is licensed under a modified GPL and can be used in commercial applications
under this license without any requirement to expose your propriatory source code.
An alternative commercial license option is also available in cases that:
You cannot fulfill the requirements stated in the "Modified GPL license" column of the table below.
You wish to receive direct technical support.
You wish to have assistance with your development.
OpenRTOSTM is a commercially licensed version of FreeRTOS. The OpenRTOS license does not contain any references to the GPL.
SAFERTOSTM is a derivative version of FreeRTOS that has been analyzed, documented and tested to meet the stringent requirements of the IEC 61508 safety standard. Complete safety lifecycle documentation artifacts have been created and independently audited to verify IEC 61508 SIL 3 conformance.
The FreeRTOS source code is licensed by a modified GNU General Public
License - the modification taking the form of an exception. The full text
of the GNU General Public License is available here.
The text of the exception is available at the bottom of this file.
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 exception itself.
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.
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.
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.
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
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 demo applications.
The files contained within FreeRTOS\Demo\WizNET_DEMO_TERN_186\tern_code,
which are slightly modified versions of code provided by and copyright to
Errors and omissions should be reported to Richard Barry, contact details for
whom can be obtained from the Contact page.
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, provided that
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.
The combined work is not itself an RTOS, scheduler, kernel or related product.
The independent modules add significant and primary functionality that is unrelated to multitasking, intertask communication or intertask signalling -
and therefore do not merely extend the 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).
Copyright (C) 2004-2010 Richard Barry. Copyright (C) 2010-2015 Real Time Engineers Ltd.
Any and all data, files, source code, html content and documentation included in the FreeRTOSTM distribution or available on this site are the exclusive property of Real Time Engineers Ltd..
See the files license.txt (included in the distribution) and this copyright notice for more information. FreeRTOSTM and FreeRTOS.orgTM are trade marks of Real Time Engineers Ltd.