Nektony has introduced VSD Viewer 1.0 for Mac OS X (10.8 and higher). It costs US$9.99 and is available worldwide exclusively through the AppStore in the Business category (http://tinyurl.com/c2ba83y).
Designed for anyone who use Visio drawings as a reference, VSD Viewer allows Mac users to open vsd files created with Visio 2000 – 2010, a file extension for a vector graphics format developed and owned by MS Visio.
Opening a Visio drawing on Mac with VSD Viewer is as simple as drag and dropping the file to its application window. VSD Viewer allows viewing of common document formatting.