A Day in Serenity @ kenjis


What is Open Software License (OSL) ?

There is Open Software License (OSL), which is not famous. This is a memo about OSL 3.0.

If you use OSLed software or adopt OSL to your software, you had better confirm OSL by yourself. If you find some errors in this article, I hope you feedback to me.

OSL is an open source license

OSL is an OSI approved Open Source License. OSI categorizes it in "Other/Miscellaneous licenses".

OSL is a copyleft license

Wikipedia says:

The OSL is a copyleft license

OSL has a copyleft clause:

1 c) to distribute or communicate copies of the Original Work and Derivative Works to the public, with the proviso that copies of Original Work or Derivative Works that You distribute or communicate shall be licensed under this Open Software License;

OSL's definition of Derivative Works is different from GPL's

Wikipedia says:

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.

OSL defines Derivative Works as below:

b) to translate, adapt, alter, transform, modify, or arrange the Original Work, thereby creating derivative works ("Derivative Works") based upon the Original Work;

There is no technical terms like "link", OSL defines it as "to translate, adapt, alter, transform, modify, or arrange the Original Work".

OSL is not compatible with GPL

FSF says:

The Open Software License is a free software license. It is incompatible with the GNU GPL in several ways.

A license is "compatible with the GPL?" means:

It means that the other license and the GNU GPL are compatible; you can combine code released under the other license with code released under the GNU GPL in one larger program.

Software licensed under OSL, which is not compatible with GPL, can not be combined with GPLed software.

OSL is a license which plugs ASP loophole

"ASP loophole" is a term to criticize a free ride to free software. If you only run free software on your server, it means you don't distribute it, so you don't have to give your source code.

AGPL is famous one which plugs ASP loophole, OSL is a license which plugs it, too.

OSL uses a term "External Deployment", using over a network also treated as a distribution.

5) External Deployment. The term "External Deployment" means the use, distribution, or communication of the Original Work or Derivative Works in any way such that the Original Work or Derivative Works may be used by anyone other than You, whether those works are distributed or communicated to those persons or made available as an application intended for use over a network. As an express condition for the grants of license hereunder, You must treat any External Deployment by You of the Original Work or a Derivative Work as a distribution under section 1(c).