Telescope or astronomy devices control
There are nearly as many different astronomical set-ups as astronomers. Lots of devices are required in a set-up, and many of each type exist. Many are not supported by free software. A hardware compatibility list is being done here.
Acquisition software generally have to handle high-end cameras, DLSR and focusers. Autoguiding software generally have to handle low-end cameras and telescope motorisations, possibly focusers too. They make very different tasks and address a large range of devices.
Telescope control: Autoguiding
See OpenPHD Guiding and GoQat. What else?
Telescope control: GoTo
GoTo functionality is generally managed by cartography software.
Image acquisition
The others has a list of software supporting each camera. Examples are GoQat for QSI cameras and Gphoto2 for DSLR.
Other devices
Filter wheels, focusers. The Hardware compatibility list lists the software supporting each devices.
Standardization initiatives
Some projects do not focus only on one particular device or even type of device, and provide abstraction layers or even try to standardize the way astronomical programs communicate with each other and with devices.
INDI is such a project for all kinds of devices.
Unicap is a way to access imagery devices.
For control of devices from various manufacturers RTS2 [1] developed an abstract device layer, enabling control of all possible combinations of mounts, CCDs, photometers, roof and cupola controllers.