One of the knock-on effects of Oracle buying Sun buying MySQL is that Monty Widenius, co-founder of MySQL, has started offering some fairly pointed commentary on the goings-on in his old company. Here's the latest one, which notes something interesting:
To be able to bootstrap MySQL Ab, we originally had a license that allowed free usage, but a "pay-for" license if you used MYSQL for commercial usage or on the Windows platform. In 2000 we changed the free license to GPL, mostly to avoid having to explain our own license to everyone.
The article continues at http://www.computerworlduk.com/community/blogs/index.cfm?entryid=2423&blogid=14