Practical LabVIEW-free Keithley 2400 front-end for Linux?
There is PyVISA for HPIB/GPIB instrument reading.  This is a wrapper around the VISA dll from NI.

There is a new effort PyVISA-py which replaces that VISA DLL.

It's a shame that most higher end instruments that you need to use in design almost certainly needs LabView.