The simple code below (in C# language) reads and displays an item value, using QuickOPC in .NET:
// Read item value and display it in a message box
"", "OPCLabs.KitServer.2", "Demo.Single").ToString());
The code below subscribes to changes of an item, and displays the value with each change:
// The callback is a lambda expression that displays the value
"", "OPCLabs.KitServer.2", "Demo.Single", 1000,
(_, args) => Console.WriteLine(args.Vtq.Value));
No other product can do this in such a clear and concise code, in a single statement! The programming is straightforward, and the developer can focus on getting the work done and not on fighting the intricacies of OPC protocols.