VDX may refer to:
- VDX (library software) (for Virtual Document eXchange), an interlibrary loan software product
- .vdx, a filename extension for the Microsoft Visio XML drawing file format
- OSEK or OSEK/VDX (Vehicle Distributed eXecutive), a standards body for automotive electronics
- Virtual Desktop Extender, a patented technology by RES Software that enables reverse seamless windows in remote desktop environments. This allows for applications that do not run well in centralized environments to be launched and viewed from within a Terminal Server, XenApp, XenDesktop, VDI or other centralized/provisioned desktop.
VDX (standing for Virtual Document eXchange) is a software product for interlibrary loan (ILL) and document request management. VDX was developed by UK company Fretwell-Downing Informatics, a company which in 2005 was taken over by OCLC PICA, itself wholly acquired by OCLC Online Computer Library Center in 2007.
VDX allows library staff to create and manage document borrowing and lending requests between participating libraries. VDX manages all the stages of the ILL process. It is also an efficient way to collect copyright fees for copyright holders such as authors and publishers.