More folks are using Linux to control equipment. Users range from amateur astronomers in the field to professional observatories.
KTelescope is a robust Client/Server control library for Meade's LX200 based telescopes. Is uses the Instrument Neutral Distributed Interface (INDI) protocol.
XEphem has the capability to communicate with a telescope control daemon process.
Apogee Instruments Inc supports their line of professional CCD cameras under Linux.
Finger Lates Instrumentation Manufacturer of CCD cameras and filter wheels and include drivers for Linux.
SBIG offers some assistance with operating their ST7 and ST8 CCD cameras under Linux.
CCD Astronomy on Linux These pages describe a number of facets of using astronomical CCD cameras for image acquisition and processing under Linux.
Gccd is a gnome-based CCD camera and filter wheel control program.