SGI Free Sofware License B
History and Most Recent Version of the SGI Free Software License B
Version 1.1 of the FreeB license was replaced by version 2.0, which mirrors the well-known X11 license. Under the terms of version 1.1, "once Covered Code has been published under a particular version of the License, Recipient may, for the duration of the License, continue to use it under the terms of that version, or choose to use such Covered Code under the terms of any subsequent version published by SGI."
Other than the added option to refer to the License's website, the terms of the version 2.0 License are identical to the terms of the X11 license. SGI decided to revise, rather than replace, the FreeB License as a matter of convenience. By revising the Free License, users will not need to update any files.
Version 1.0 of the FreeB license included one term regarding compliance with defined APIs which posed a problem for some open source developers. SGI revised the license in response to those concerns and issued a joint statement with developers outside SGI. This satisfied both SGI's needs and those of outside developers working with code covered by the FreeB license.
Version 1.0 [ html]
The version 1.0 license underwent one minor change in section 8 (defining "Modifications") on the morning that SGI released it publicly, due to internal miscommunication. The originally posted version of the license is available for reference purposes here.