Open Software License
|Publisher||2005, Lawrence Rosen|
The Open Software License (OSL) is a software license created by Lawrence Rosen. The Open Source Initiative (OSI) has certified it as an open-source license, but the Debian project judged version 1.1 to be incompatible with the DFSG. The OSL is a copyleft license, with a termination clause triggered by filing a lawsuit alleging patent infringement.
Many people in the free software / open-source community feel that software patents are harmful to software, and are particularly harmful to open-source software. The OSL attempts to counteract that by creating a pool of software which a user can use if that user does not harm it by attacking it with a patent lawsuit.
 Key features
 Patent action termination clause
The OSL has a termination clause intended to dissuade users from filing patent infringement lawsuits:
- 10) Termination for Patent Action. This License shall terminate automatically and You may no longer exercise any of the rights granted to You by this License as of the date You commence an action, including a cross-claim or counterclaim, against Licensor or any licensee alleging that the Original Work infringes a patent. This termination provision shall not apply for an action alleging patent infringement by combinations of the Original Work with other software or hardware.
 Warranty of provenance
Another goal of the OSL is to warrant provenance.
- 7) Warranty of Provenance and Disclaimer of Warranty. Licensor warrants that the copyright in and to the Original Work and the patent rights granted herein by Licensor are owned by the Licensor or are sublicensed to You under the terms of this License with the permission of the contributor(s) of those copyrights and patent rights.
 Comparison with the LGPL/GPL
The OSL is intended to be similar to the LGPL. Note that the definition of Derivative Works in the OSL does not cover linking to OSL software/libraries so software that merely links to OSL software is not subject to the OSL license.
The OSL is not compatible with the GPL. It has been claimed that the OSL is intended to be legally stronger than the GPL, however, unlike the GPL, the OSL has never been tested in court and is not widely used.
 Assent to license
The restriction contained in Section 9 of the OSL reads:
- If You distribute or communicate copies of the Original Work or a Derivative Work, You must make a reasonable effort under the circumstances to obtain the express assent of recipients to the terms of this License.
In its analysis of the OSL the Free Software Foundation claims that "this requirement means that distributing OSL software on ordinary FTP sites, sending patches to ordinary mailing lists, or storing the software in an ordinary version control system, can arguably be a violation of the license and would subject violators to possible termination of the license. Thus, the OSL makes it challenging to develop software using the ordinary tools of Free Software development."
If the FSF claim is true then the main difference between the GPL and OSL concerns possible restrictions on redistribution. Both licenses impose a kind of reciprocity condition requiring authors of extensions to the software to license those extensions with the respective license of the original work.
 Patent action termination clause
The patent action termination clause, described above, is a further significant difference between the OSL and GPL.
 Further provisions
- Derivative Works must be distributed under the same license. (§1c)
- Covered works that are distributed must be accompanied by the source code, or access to it made available. (§3)
- No restrictions on charging money for programs covered by the license, but source code must be included or made available for a reasonable fee. (§3)
- Covered works that are distributed must include a verbatim copy of the license. (§16)
- Distribution implies (but does not explicitly state) a royalty-free license for any patents embodied in the software. (§2)
 Later versions
It is optional, though common for the copyright holder to add “or any later version” to the distribution terms in order to allow distribution under future versions of the license. This term is not directly mentioned in the OSL. However, it would seem to violate section 16, which requires a verbatim copy of the license.
 Open software that uses the OSL
- ClearCanvas, Enterprise-ready DICOM Viewer and RIS/PACS.
- CodeIgniter v3.0 (planned), an open source PHP framework.
- Magento, an eCommerce web application.
- PrestaShop, an eCommerce web application.
- Mulgara, a triplestore written in Java (new code is being contributed using the Apache 2.0 license).
- Sparse, a static code analysis tool designed for the Linux kernel.
 Open software that used the OSL
- NUnitLite up to 2.0 Alpha, a lightweight version of NUnit, NUnitLite is available under MIT / X / Expat Licence
 See also
- "Open Source Initiative OSI – The Open Software License 3.0 (OSL-3.0:Licensing | Open Source Initiative". Opensource.org. Retrieved 2012-03-04.
- "DFSGLicenses – Debian Wiki". Wiki.debian.org. 2012-02-29. Retrieved 2012-03-04.
- "Open Source Initiative OSI - The "Open Software License":Licensing". Opensource.org. 2006-05-01. Archived from the original on 2006-05-01. Retrieved 2012-10-15.
- "BusinessWeek". BusinessWeek. 2006-02-06. Retrieved 2012-03-04.
- "LinuxElectrons - Apache Software Foundation Position Regarding Sender ID". Linuxelectrons.com. 2005-10-31. Archived from the original on 2005-10-31. Retrieved 2012-10-15.
- "Open Software License (“OSL”) v. 3.0" (PDF). Retrieved 2012-10-15.
- "Philosophy of the GNU Project – GNU Project – Free Software Foundation (FSF)". Gnu.org. 2012-02-26. Retrieved 2012-03-04.
- "Choosing an Open Source License". Airs.com. Retrieved 2012-03-04.
- "Various Licenses and Comments about Them – GNU Project – Free Software Foundation (FSF)". Gnu.org. Retrieved 2012-03-04.
- Open Software License v.3.0 by Lawrence Rosen, 2005, Retrieved September 10, 2006
- Open Software License v.1.1 by Lawrence Rosen, 2005, Retrieved September 10, 2006
- OSL 3.0 Explained by Lawrence Rosen, 2007, retrieved January 8, 2008
- Nuclear War over Software Patents? by Lorraine Woellert, "BusinessWeek Online", February 6, 2006, Retrieved September 10, 2006
- From: "Lawrence Rosen" Subject: RE: Microsoft's amended Sender ID license by Lawrence Rosen, August 24, 2004, Retrieved September 10, 2006
- Philosophy of the GNU Project by the Free Software Foundation, Retrieved September 10, 2006
- Choosing an Open Source License by Ian Lance Taylor, 2005, Retrieved September 10, 2006