A plugin for SolidWorks; the "solid post" would be the machine-specific driver.
The .rar extension indicates a compressed folder. Users often share these files on technical forums or peer-to-peer sites when they have a "solid" (functional and tested) configuration for a specific machine. POST-10.rar
In manufacturing, a "post" or "post processor" is a script or file used to translate generic toolpaths from CAM software into specific G-code that a particular CNC machine (like a 3-axis mill or a lathe) can understand. A plugin for SolidWorks; the "solid post" would
Alternatively, in the context of Usenet or binary newsgroups, "post 10 rar" can simply mean the 10th volume of a multi-part compressed file set. Potential Software Associations A plugin for SolidWorks