This page contains free Downloads as well as Services for OPC users and developers.
OPC Lookup Version 1.0
Tool for displaying description for Error and Quality Codes (.NET Framework required)
OPC UA Downloads (Freeware and Evaluation Version)
Downloads from Unified Automation GmbH
Free OPC UA Client for Windows and Linux, Evaluation and Demo Downloads for OPC UA Servers (registration required)
Services for developers
Online service converting Error and Quality Codes into official text messages