Why GPLv3 Will Supplant GPLv2
One of the most important recent events in the world of free software has been the release of version 3 of the GNU GPL. There were fierce arguments about its utility while it was being drawn up, and although the rhetoric has abated somewhat, there is still a big question mark over its eventual success. Some evidence suggests that GPLv3 uptake is coming along nicely, while other reports indicate a reluctance to adopt it (but note also Matt Asay's neat reconciliation of these contradictory messages). To see what's likely to happen in the long term, it's useful to look back at the past history of licence adoption.
The first detailed discussion about licences arose when companies began offering open source software other than GNU/Linux distributions. Many were rather timid or even downright sceptical about embracing the GNU GPL wholeheartedly, and chose instead to adopt a dual licensing policy, offering a version of the software (sometimes with extra features) under a non-free licence as well as a version under the GNU GPL. This was pioneered by L. Peter Deutsch with Ghostscript.
Ghostscript was the direct inspiration for the early dual-licensing approach of MySQL, where initially the free licence employed was not the GNU GPL. As MySQL's CEO, Marten Mickos, told me last year: