There was a download of TachyCAD 9.0.10.4 on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. The program relates to Photo & Graphics Tools. We recommend checking the downloaded files with any free antivirus. This free program is an intellectual property of kubit GmbH. The following versions: 9.0, 6.0 and 4.0 are the most frequently downloaded ones by the program users.
From the developer:
TachyCAD works as a direct plug-in to the latest versions of AutoCAD and AutoCAD LT. This program is a solution for measured building surveys which make it easy for anyone, expert or amateur, to achieve precise and efficient results. It is designed for fast and efficient on-site surveying and data capture.
You may want to check out more software, such as CAD To DMC, GeoMoS or Template Package Flat Panel, which might be related to TachyCAD.