What it is
OPC UA client libraries for your own programs: the same few functions in five languages, .NET, Python, JavaScript/TypeScript, C/C++ and Rust. Connect, read, write, browse and subscribe; the data type comes from the server, none to declare. Reconnects, restored subscriptions and the client certificate are handled by the library. Works with any OPC UA server.
IDE tools: a node browser in Visual Studio and VS Code (drag a tag into the code), and tag names completed and checked in the editor.
Licence: one developer, perpetual, all five languages. Royalty-free: no fee per installed program. Updates and support for the first year included. Delivered as an installer with the libraries also in plain folders, and the manual.
Updates and support from the second year: 120 € a year, optional. The libraries keep working without it.
Product page: https://opc2all.com