In terms of the major database companies, you could argue that Oracle was relatively slow to jump onto the Linux bandwagon, or you might argue that IBM was fast off the mark.
It probably happened that way because IBM was getting anxious about platforms. The world had gradually moved to Unix or Windows NT and the reference platform for Unix was Sun's Solaris, not IBM's AIX. When Linux started to become popular, IBM was quick to see an advantage. No vendor owned Linux and IBM could use it to sell its hardware and make it a prime platform for its software.
Anyway, Oracle is now clearly a Linux convert and evangelist. It is running an expensive world-wide marketing campaign under the slogan "Unbreakable Linux". As part of this it is spending $150 million to encourage ISVs to develop Oracle based applications for the Linux platform, offering help with porting and development (all in a free Linux bundle). All its products are available on Linux and it claims to "recommend Linux to many of its new customers". Oracle is also eating its own food, as it runs its own business on Linux.
The article continues at