This section contains downloadable documentation for ASCOM, both Alpaca and COM, as well as conceptual documents that cover both. These documents cover ASCOM theory, ASCOM-COM, and ASCOM Alpaca in more depth than the About Ascom section here on this web site. End Users and Developers, if you are starting from scratch it is recommended that you first read through the About ASCOM section so that you have a basic understanding of the design objectives and implementation concepts. This way you can avoid getting the details from these documents within a framework of preconceived ideas which may not be appropriate.
If you want to learn about ASCOM, including why it exists, what it does for astronomy technology, its computing and design roots, and where it's going in the future, this is where to go. 
German Equatorial mount behavior is frequently misunderstood. This document describes the terminology and behavior expected via ASCOM interfaces (and of course the Conformance Checker tool) with regard to German mount pointing state and side of pier. It's vital for developers to understand the meaning of the terms, the geometry, and German mount behavior. This is a FAQ format document that answers some common questions about Alpaca.
This covers the fundamentals of Alpaca at a fairly detailed level, including its Application Programming Interfaces (APIs), device discovery, app-driver relationships, and ways in which it may be used and Interoperability with classic ASCOM on Windows via ASCOM Remote. User's Guide to ASCOM Remote, the middleware that provides a bridge between ASCOM COM and ASCOM Alpaca. This document is also included with ASCOM Remote.This is an online copy of the comprehensive help information that is part of the ASCOM Platform for Windows. This contains a wealth of information on the Chooser and end-user tools that are provided as part of the ASCOM Platform. This info is also installed as part of the ASCOM PLatform and is easily accessible via the usual Windows Start button's menus.This is an online copy of the master implementation neutral ASCOM interface definitions. This is the definitive reference for the various device interface (patterns) and the detailed functions/methods and variables/properties. These abstract definitions apply to both ASCOM Alpaca and ASCOM COM. This is an online copy of the comprehensive help information that is part of the ASCOM Platform Developer Components. This contains a wealth of developer and reference information about "classic" ASCOM on Windows (using COM). The ASCOM Library provides a broad set of enabling components that make it easier to develop ASCOM clients (both COM and Alpaca), Alpaca devices, and COM drivers. This cross platform library can be used for projects that target .NET (C#) on Linux, Raspberry Pi, MacOS and Windows.
This document is the technical reference for the ASCOM Alpaca APIs and describes how to use them. Also described is the ImageBytes High Speed Image transfer Protocol, as well as the Alpaca Discovery protocol and some of the fundamental behavioural principles that underly the APIs and their effective exploitation. These device APIs are the REST-like (HTTP/JSON) implementations of the master implementation neutral definitions listed above.
This is a live API reference and test document. It provides a structured description of each endpoint for all ASCOM device APIs as well as the Alpaca Management API. With this document you can exercise the Alpaca APIs with live data and see the results. It uses a "mocked" implementation of each device and the management server. The devices will not exhibit real behavior. You can only see how the Alpaca API itself works. This is a reference to the Standards section here in which the principles on which decisions on creating new interfaces and modifying existing ones are made. Understanding these principles that guide our decision processes may help you understand why the interfaces are the way they are.German Equatorial mount behavior is frequently misunderstood. This document describes the terminology and behavior expected via ASCOM interfaces (and of course the Conformance Checker tool) with regard to German mount pointing state and side of pier. It's vital for developers to understand the meaning of the terms, the geometry, and German mount behavior. This covers the fundamentals of Alpaca at a fairly detailed level, including its Application Programming Interfaces (APIs), device discovery, app-driver relationships, and ways in which it may be used and Interoperability with classic ASCOM on Windows via ASCOM Remote. User's Guide to ASCOM Remote, the middleware that provides a bridge between ASCOM COM and ASCOM Alpaca. This document is also included with ASCOM Remote.This is a live API reference in "Read the Docs" format. The package provides all of the ASCOM Standard universal interfaces to astronomical devices using the Alpaca network protocol. Installs via pip install alpyca. As an application developer, your usage of the various devices is simplified and universal (API level), independent of the particular make/model of device. Here are the docs in PDF format (download).
Copy of the instructions for the Alpaca Workbench. This doc tells how to use the Omni Simulators, Conform Universal, and Wireshark in the context of developing apps and devices that speak Alpaca. Updated April 2023 for the current versions of the Omni Simulator and Conform Universal. This document is contained within the downloaded workbench archive.