SiteWorx/OS 4.0.2.70 could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this software available.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. The most frequent installation filename for the program is: SiteWorxOS.exe. The software belongs to Photo & Graphics Tools. This program is an intellectual property of Vertigraph, Inc. Also the tool is known as "SiteWorxOS". The most popular versions among SiteWorx/OS users are 4.0 and 3.1.
From the developer:
When calculating cuts and fills, SiteWorx/OS eliminates the need for paper plans. With SiteWorx/OS digitize directly from TIFF, PDF, DXF and many other raster and CAD format files. Easily digitize with your mouse existing and proposed contour lines, spot elevations and areas along with project boundaries, topsoil strip areas and topsoil respread areas.
You may want to check out more software, such as StoneCAD, Trace Parts or General Cadd Pro - FULL, which might be similar to SiteWorx/OS.