CUI File

What are CUI files and how to open them

Are you having problems opening a CUI file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your CUI files.

What is a CUI file?

CUI files have multiple uses, and AdaProbe Debugging Info is one of them. Read more about the other uses further down the page.

AdaProbe Debugging Info

AdaProbe Debugging Info files store debugging metadata produced by Alsys's Ada development tools. These files are generated when Ada units are compiled with debugging support (for example using the -d or -D options with Alsys' compiler and the binder is run with those flags). They pair with an Ada executable to hold source-level debug information such as symbolic names, variable types, call history, and mappings from compiled units back to source code. This lets the AdaProbe debugger examine program units, set breakpoints, display or modify variable contents, and trace the execution of source code without embedding debug code directly into the executable itself.

The files are read by the AdaProbe debugger (part of the ActivAda / Alsys toolset) during a debugging session. The executable is not altered by their creation. When compiling, developers include debugging flags so the compiler and binder produce one of these metadata files (typically named executable.cui). During debugging, AdaProbe uses the metadata to resolve source locations, display variable names and values, show the call stack, and allow stepping through source or machine instructions where supported.

Internal structure starts with the ASCII signature CUIb at the very beginning, and these files include characteristic strings like ADAPROBE_SUPPORT and ­_VV.VVALSYS which help tools or file-identifiers recognize them.

How to open CUI files

Important: Different programs may use files with the CUI file extension for different purposes, so unless you are sure which format your CUI file is, you may need to try a few different programs.

We have not yet verified any programs for Windows that work with this specific file format. If you know one, please use the 'Suggest a program' link below. Thanks!

Last updated: September 19, 2026

All known file formats using extension .CUI

While AdaProbe Debugging Info is a popular type of CUI-file, we know of 3 different uses of the .CUI file extension. Different software may use files with the same extension for different types of data.

AutoCAD Custom User Interface

We know that one CUI format is AutoCAD Custom User Interface. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

We have not yet verified any programs for Windows that work with this specific file format. If you know one, please use the 'Suggest a program' link below. Thanks!

QuarkXPress Color Library UI Specs

QuarkXPress Color Library UI Specs files store settings that control how a color library appears in the QuarkXPress user interface. They define layout details for displaying color swatches in the Colors palette - such as how many swatches show per page, what prefix or suffix to display on each color name, and how columns or pages are structured - separate from the color data itself. These specs are part of Quark's XML-based color library system, adapted from the CGATS.17 standard.

They are generated by QuarkXPress and paired with a companion file that holds actual color definitions. When QuarkXPress starts, it loads both the color-data file (with extension .qcl) and the UI spec file for each library found in its Color folder. The UI spec does not hold color values but only defines how the colors will be presented visually: number of rows per page, name prefix or suffix, and other UI-layout attributes.

The file begins with the XML declaration signature <?xml version="1.0"?> and includes XML tags such as LibraryUISpecs, edit_dialog_data, rows_per_page, color_ui_prefix, color_ui_suffix, column_data, etc. These internal identifiers and tag names help distinguish the format from other .CUI types.

We have not yet verified any programs for Windows that work with this specific file format. If you know one, please use the 'Suggest a program' link below. Thanks!

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