GroupDocs.Metadata for .NET is described as 'provides public classes and interfaces to create, manipulate, clean, search and compare metadata associated with Microsoft Office Document, Email, PDF and Image formats' and is an app in the Office & Productivity category. There are four alternatives to GroupDocs.Metadata for .NET for a variety of platforms, including Windows, .NET Framework, Citrix XenCenter, Linux and Mac. The best alternative is cleanDocs. It's not free, so if you're looking for a free alternative, you could try mat2. Other great apps like GroupDocs.Metadata for .NET are Workshare Protect (Paid) and Batch Edit Office Properties (Paid).
cleanDocs is a metadata removal tool. It protects organizations from accidental information and metadata leaks. cleanDocs integrates tightly with email systems to ensure all hidden metadata is removed from documents sent outside of an organization.
mat2 is a metadata removal tool, supporting a wide range of commonly used file formats, written in python3: at its core, it's a library, used by an eponymous command-line interface, as well as several file manager extensions.