OPC Data Client uses “boxing”, a special technique based on file system and registry virtualization, which allows is to transparently load and use dependent software that would otherwise have to be installed (and uninstalled separately). With boxing, OPC Data Client libraries can simply be placed on disk, registered (for COM) and referenced from .NET or COM code, without installing other software.

The boxing encompasses following software:

1. Microsoft Visual C++ Redistributable for Visual Studio 2015, 2017 and 2019 (x86, x64). From Microsoft Corporation.
   Needed because parts of our software are written in managed C++ (for OPC Classic only).
2. OPC Core Components 3.00 Redistributable (x86 or x64). From OPC Foundation.
   Provides proxies/stubs that allow OPC "Classic" components to communicate, and a server enumeration facility (OPCEnum) for a discovery of OPC "Classic" servers.

In order to improve application startup speed, conserve memory, or in edge cases where the “boxing” approach fails, a user can still install any of the above prerequisites, and OPC Data Client will use the software installed on the disk. The download links for the individual prerequisites for such case are installed with OPC Data Client, under the Redist folder (“Redistributables” from the program group under Start menu).