What is a .HDX file?
The .HDX file extension is associated with a specific type of file known as a Delphi MultiHelp Index File. This kind of file is essentially a help documentation file. It was primarily used by older versions of a popular design software called AutoCAD. AutoCAD is a software application used for designing and drafting in various fields such as architecture, engineering, and construction.
The .HDX file typically goes by the name ACAD.HDX. Its main function is to provide an index or a guide for another file, which is called ACAD.HLP (with the .HLP file extension). The .HLP file contains the actual help documentation or instructions. Together, the .HDX file helps users navigate through the help documentation more efficiently by indexing the contents of the .HLP file.
It's important to note that recent versions of AutoCAD no longer use the .HDX file format. This means that the .HDX file is somewhat outdated and might not be compatible with the latest AutoCAD software versions.
However, if you are using an older version of AutoCAD or have a need to access help documentation from an older version, you might encounter the .HDX file. To open an .HDX file, you would typically use Autodesk AutoCAD, specifically a version that supports this file type. As of my last update in 2023, Autodesk AutoCAD 2023 is mentioned as a program that can open this file extension, but this might be an oversight, as newer versions of AutoCAD have moved away from using .HDX files. Therefore, if you're working with .HDX files, ensure you're using a compatible version of AutoCAD that recognizes and supports this file format.
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