Alpaca is the new protocol from the ASCOM community for controlling astronomy equipment. Alpaca is 100% backwards compatible with ASCOM but instead of using COM (Component Object Mode) which is exclusive to Windows, Alpaca uses HTTP and JSON for data communications. This allows it to run across multiple machines in a client/server or user/driver mode. It also allows you to use any platform you want and no longer are tied to Windows. In fact you can run the system with no Windows machines at all.
AlpacaPi is my implementation of the Alpaca protocol to run on Linux, specifically it was designed to run on the Raspberry-Pi, which is why I call it AlpacaPi. It will run on just about any flavor of Linux and will run on both 32-bit and 64-bit Linux.
AlpacaPi implements all of the drivers in one application. On startup, it looks to see what is attached, for example if it discovered 2 ZWO cameras and 1 ATIK Camera, it would create 3 camera drivers (0,1,2) that could be used interdependently. I have actually done this and it works just fine.
My normal configuration in my observatory is 3 imaging scopes on one mount, each of a different size.
Each one has one Raspberry-Pi to control it.
Each imaging setup has
a filter wheel,
a Moonlite NiteCrawler focuser which is implemented as a focuser AND a rotator.
This only requires one copy of the alpacapi driver, which handles all of 4 of the above listed devices.
AlpacaPi is written in C/C++ and runs on Linux, it is open source. https://github.com/msproul/AlpacaPi