Open Software License
| Author | Lawrence Rosen | 
|---|---|
| Latest version | 3.0 | 
| Publisher | 2002, Lawrence Rosen | 
| SPDX identifier | OSL-1.0, OSL-1.1, OSL-2.0, OSL-2.1, OSL-3.0 | 
| FSF approved | Yes | 
| OSI approved | Yes | 
| GPL compatible | No | 
| Copyleft | Yes | 
| Website | opensource | 
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 and 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.