If you are interested in using LabVIEW and NIDAQmx and/or NIDAQmx-base on Slackware 12.0 it is actually easier than with previous versions - with one major caveat.
1. Be sure to download Visa 4.2.0 and install it before either NIDAQmx or NIDAQmx-base (or NI488225L either).
2. As near as I can tell, the version or rpm shipped with 12.0 still won't allow you to install into anything but the default directory. So for NIDAQmx-base (at least for version 2.1) you need to edit the install script and remove from all the rpm commands the option "--prefix [some prefix value]" - it will then install fine in the default locations.
3. I didn't notice any problems with either NIDAQmx or NI488225L - they both seemed to just install.
4. The install script for LabVIEW 8.2 still has a couple of lines in it that disable rpm if running on slackware. If you have followed the earlier instructions to populate the rpm database then you can comment out those few lines and allow the installer to use rpm. If you haven't populated your rpm database then you can go ahead and use the non-rpm install but I have had problems with things not getting installed correctly with previous versions. I didn't try the non-rpm install on either LabVIEW 8.0 or 8.2. I haven't tried either with 8.5.
5. The kernel shipped with Slackware 12.0 (2.6.21.5) does not - as near as I can determine - work properly with DAQmx-base and at least the USB6009 acquisition module. I had to drop back to a version 2.6.19.7 kernel before it would work. I haven't been able to find a reason for the failure - it just says it can't read the configuration information from the device even though it works fine on 2.6.19.7.