Sun has apparently notified the Open Source Initiative that the Sun Public License (SPL) is no longer of use to the open source community. On his blog, Sun's Chief Open Source Officer Simon Phipps wrote:
....one of the very first things we did when I became Sun's Chief Open Source Officer in 2005 was to start the process of simplifying Sun's approach to licensing by retiring an old open source license, SISSL, which I assume no responsible company will now choose to use.
Following the OSI's lead, the time has come to further simplify, and I'm pleased to be able to announce that Sun has contacted OSI again and informed them that another license Sun created - the Sun Public License, or SPL - is no longer required by Sun and requested that they consider it "retired". We migrated the last large codebase from it last spring - NetBeans - and it's now a historical artefact.
With 58 licenses currently on the Open Source Initiative's approved license list, many of which are not compatible with each other (meaning code that's licensed under one license can't be merged open source style with code licensed under another), retiring licenses in the name of anti-proliferation can only be a good thing.