Free Visio Viewer software (version 1.0) is a tool that allows users to view Visio files without requiring a license for Microsoft Visio. The software supports various file formats, including VSD, VDX, VSDX, and VSDM. Users can zoom in and out, pan, and rotate the diagram to view it from different angles. Additionally, the software allows users to print the diagrams or save them as image files such as PNG, BMP, or JPEG.