Visio is a diagramming tool included as part of the Microsoft Office suite. This tag is only for questions on programming against Visio objects or files—also tag with VBA.
Visio is a diagramming tool included as part of the Microsoft Office suite, though it is usually acquired separately. It is used to create documents such as flowcharts, organizational charts, network topologies, and software architecture diagrams. Visio includes a development environment known as the ShapeSheet and an API which can be used to develop diagraming and data visualization applications.
Ask programming-related questions about Microsoft Visio (ShapeSheet, API, UML, flow charts, database diagrams, etc.) here on Stack Overflow. For non-programming applications of Visio and for general Visio support, consider if your question might be a better fit on Super User.
Documentation: