| 32bit and 64bit linux is actually very similar. Linux has tried to use the same codebase for both, so the code for a 32bit driver should be the same (or very similar to) code for a 64bit driver. This is mainly due to the open source nature, and the fact that people have 64bit platforms already.
64bit Windows is going to take a bit longer, as you have to wait for a manufacturer to release 64bit drivers. Some manufacturers have been very good with this, such as nVidia. Others have been the opposite, and claimed they have no plans to write 64bit drivers.
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