A software development kit that allows you to simply and easily add an OPC-UA Server to your microcontroller based product. With an emphasis on efficient RAM usage, the SDK is optimized for microcontrollers with 64kB 512kB RAM.

• Robust, scalable solution developed from first principles for embedded systems.
• True ANSI C multiplatform software that runs on any OS or RTOS or even on bare-metal systems.
• Runs on a $5 microcontroller and supports the smallest RAM footprint in the industry.
• Incredibly easy to use with prototype development in days, not weeks or months.
• No heap based memory allocation is used to ensure maximum reliability.

Product Details: http://www.embeddedlabs.com/products/opc-ua_device_server_sdk_mcu.html 

A software development kit for enhanced embedded systems based on high performance processors such as ARM9 and Intel Atom. With an emphasis on performance and large data sets, the SDK enables your device to serve thousands of variables to large numbers of concurrent clients.

• Robust, scalable solution developed from first principles for embedded systems.
• True ANSI C multiplatform software that runs on any OS or RTOS or even on bare-metal systems.
• The number of sessions, subscriptions, monitored items and address space nodes supported is solely dependent on your available target resources.
• Incredibly easy to use with prototype development in days, not weeks or months.
• Both SDKs use a common API allowing seamless migration of application code across targets.

Product Details: http://www.embeddedlabs.com/products/opc-ua_device_server_sdk_mpu.html 

Ignition OPC-UA is a cross-platform OPC-UA Server for industrial control systems. It features a free open-driver API and a free software development kit to create your own drivers.

• Cross platform.
• High performance network architecture.
• Non-blocking I/O.
• Free.
• Written in 100% Pure Java.

Product Details: http://www.inductiveautomation.com/scada-software/opc-ua-server 

Prosys OPC UA Java SDK enables efficient development of OPC UA clients & servers, and also applications such as data acquisition, monitoring, user interfaces, and device diagnostics, etc. The components allow you to concentrate on the application design instead of communications reducing development time and cost. The reliability and usability of the components has been verified and the components take care of important communication details. With this SDK you create royalty free compiled applications which maximize flexibility and cost savings during application distribution and installation.

Supported OPC UA Information models:

• Data Access
• Historical Access
• Alarms & Conditions

Product details: http://www.prosysopc.com/opc-ua-java-sdk.php

The OPC Toolbox UA is a suite of high-end toolkits for easy and rapid development of OPC UA Clients and Servers for Windows, Windows CE, Linux, VxWorks, QNX, and more platforms.

• Fast time-to-market and cost savings: Lean programming interface allows very easy use of full OPC UA functionality and reduces effort and time-to-market for your OPC UA developments.
• Robust and high performance: Suitable for continuous operation with several hundred thousand data points and for use in time-critical control tasks.
• Support and security: The Softing OPC Competence Center and our international update and support program provide optimum assistance in your OPC UA product developments and long-term protection of your investments.

Product Details: http://www.opc-unified-architecture.com/ 

Server and Client SDK/Toolkit includes precompiled libraries + header files, documentation and samples. The full edition supports all basic OPC UA Services, DA Profile, A&C, History and Programs and is available in binary or full source code edition and also includes an information model designer and code generating tool (UaModeller) to speed up development and increase coding quality.

• Platform independent Server SDK & Toolkit for the development of full-featured OPC UA Servers.
• Designed for PC platforms and enhanced embedded Systems including Windows 64, Linux 64, Windows CE 5 and 6, vxWorks 6.6, QNX Neutrino 6.x, tenAsys INtime 3.1 and 4.0, Solaris10, Euros 3.20.
• Portable C++ class library.
• Tested on following CPUs: x84 32bit and 64bit, ARM7, ARM9, ARM 11, Atom and PowerPC), tested for compliance using the latest CTT and tested at the latest IOP Workshop.
• Provided with sample implementations for Windows and Linux.

Product Details: http://www.unified-automation.com/c++-based-opc-ua-server-sdk.htm

ANSI C Based OPC UA Server SDK/Toolkit

The ANSI C Server SDK/Toolkit is designed for use within embedded devices. The code is optimized for maximum portability and minimum resource consumption. The full edition supports all basic OPC UA Services DA Profile, A&C, History and Programs and is available as full source code only and also includes an information model designer and code generating tool (UaModeller) to speed up development and increase coding quality.

• Platform independent Server SDK & Toolkit for the development of optimized embedded UA Servers available for Windows 64, Linux 64, Windows CE 5 and 6, vxWorks 6.6, QNX Neutrino 6.x, tenAsys INtime 3.1 and 4.0, Solaris10, Euros 3.20.
• Designed to work with limited resources and maximum performance thanks to its small memory footprint and small code size.
• Portable ANSI C toolkit, works in a single task / single thread environment.
• Provided with sample implementations for Windows and Linux.
• Tested on following CPUs: x84 32bit and 64bit, ARM7, ARM9, ARM 11, Atom and PowerPC), tested for compliance using the latest CTT and tested at the latest IOP Workshop.

Product Details: http://www.unified-automation.com/ansi-c-based-opc-ua-server-sdk-for-embedded.htm