An HTM file, often found with the extension html, is a hypertext markup language file. Html is a text-based markup language (markup: award), which is mainly used for websites.
In addition to the actual content that should be displayed on a web page, an html file also includes awards for how to display and structure something. For example, html also includes images on the website and defines which text is a link and where it should lead.
Generally you can open html files with any text editor, but of course you only get to see the pure source code. For better readability you should use a text editor with programming language recognition (eg Notepad ++) or use a real website editor. Htm files can also be opened and edited with Microsoft Word or Open Office Write, but it is not recommended.
A web browser is sufficient to display an HTM file as a web page. Embedded files, such as images, must be in the location referenced in the HTM file for correct representation. Web browsers such as Mozilla Firefox or Internet Explorer also create an HTM file by saving a web page along with a folder that contains the images and other items.
Most often resolving problems with opening HTM files is very simple. Just install an appropriate program that supports such files. All of the listed programs support HTM files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of HTM files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate HTM files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Safari applications is not on the list, select "Browse" option in order to manually locate the directory where Safari has been installed.
Sometimes problems with opening HTM files may not lie with the application itself, but can arise due to other causes, such as: