CML File

What are CML files and how to open them

Are you having problems opening a CML 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 CML files.

What is a CML file?

CML files have multiple uses, and Chemical Markup Language Document is one of them. Read more about the other uses further down the page.

Chemical Markup Language Document

These CML files contain chemical information used by chemists. The data stored includes molecules, reactions, analytical data, and chemical materials. It is used for information management about specific chemicals.

How to open CML files

We have identified one CML opener that is compatible with this specific type of CML file.

Programs that open Chemical Markup Language Document files

Last updated: August 31, 2026

All known file formats using extension .CML

While Chemical Markup Language Document is a popular type of CML-file, we know of 3 different uses of the .CML file extension. Different software may use files with the same extension for different types of data.

ChordML Music Document

ChordML Music Document is an XML‐based format for storing simple chord sheets: the series of chord symbols, lyrics, repetitions, meta-information (title, author) and section divisions of a song. It is meant for songs in genres like pop or folk, not for fully notated scores (staffs, precise rhythms etc.). It allows capturing chords aligned with lyrics, repeated sections, and basic structure without full musical notation.

ChordML files are created by music authors or enthusiasts using text editors or tools that support the ChordML grammar, writing out XML that conforms to its DTD. It is human-readable, intended for interchange or archival of chord + lyric arrangements, and to support simple querying or display of chord progressions. Frequently they are converted into chord charts or used in applications that display lyrics with chord symbols above or inline.

Files begin with the XML declaration, e.g. <?xml version="1.0"?>, include a DOCTYPE declaration specifying CHORDML, and contain elements such as TITLE, AUTHOR, IDIOM (style or genre), INTRO, BODY, and tags for repetitions and sections. Signature patterns include a "<!DOCTYPE CHORDML>" string and keyword fields like CHORDML TITLE AUTHOR IDIOM INTRO BODY inside the XML.

While we have not verified the apps ourselves yet, our users have suggested eight different CML openers which you will find listed below.

UniComal COMAL 80 Library

UniComal COMAL 80 Library files are binary program libraries used with COMAL-80, a structured programming language developed by UniComal ApS (Denmark) and associated with the COMAL-80 system. These library files store pre-compiled or packaged procedures and modules in a compact form so that COMAL programs can use them without reloading or recompiling the source during each session. Common COMAL 80 environments for IBM PC or Commodore 64/128 allow routines and extensions (graphics, sound, etc.) to be linked in or loaded from these library files to extend functionality.

These library files are created by the SAVE or PACKAGE mechanisms provided by the COMAL-80 system of UniComal. Program routines, often in machine-code or pre-assembled form, are stored in the library; during program execution the libraries are linked or activated by commands such as LINK or USE so that their routines become available. The library format is optimized for efficient load and execution rather than human readability, unlike LIST or text source file formats. Such library files generally cannot be viewed or edited in a plain text editor.

Various apps that use files with this extension

These apps are known to open certain types of CML files. Remember, different programs may use CML files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about CML file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.