QuickOPC is a set of .NET components that simplify the task of integrating OPC into applications. It works in the "original" .NET Framework, and it also supports the new .NET Standard specification. This allows programs written with QuickOPC to run in different runtimes and on different operating systems; most importantly, not just on Microsoft Windows, but also on Linux, with the .NET Core runtime.
Have a look at the .NET Framework page for the description of the product features - what you find there, applies to .NET Standard as well, wherever possible.
If you have previously developed with QuickOPC for .NET Framework and are now transitioning to .NET Standard, you may continue to use your existing code, as there are practically no coding differences between the two.There are, however, differences in other aspects, such as the supported functionality, tooling, installation, security, user interface, deployment, use of examples, etc.; more details.
When you target .NET Standard, OPC Unified Architecture and OPC XML-DA are directly supported.
You can use Visual Studio 2017, .NET CLI Tools, JetBrains Rider, Visual Studio Code, or other tools to develop with QuickOPC for .NET Standard.
Simple QuickOPC Code Example in C#
The code below subscribes to changes of a monitored item value, and displays the value with each change. It runs in multiple .NET runtimes supporting .NET Standard, on Microsoft Windows or Linux:
// The callback is a lambda expression that displays the value
"http://opcua.demo-this.com:51211/UA/SampleServer", "nsu=http://test.org/UA/Data/;i=10853", 1000,
(_, args) => Console.WriteLine(args.AttributeData.Value));
Footnote & required disclosure: QuickOPC (including its Options) is a software development kit (SDK) for development of OPC clients. Installing QuickOPC or its Options does not change system settings.