.MD File extension

An MD file is a text file created using one of several possible dialects of the Markdown language. It is saved in plain text format but includes inline text symbols that define how to format the text (e.g., bold, indentations, headers, table formatting). MD files are designed for authoring plain text documentation that can be easily converted to HTML.

MD files are not only useful for HTML documentation systems, but also for source code version control. This is because the files can be compared against historical revisions in human-readable text (whereas a binary format cannot be easily compared). Projects created with GitHub, a popular online version control system, often use a file named README.md, which contains the readme for the project. John Gruber, the developer of Markdown, has created a Perl program for converting Markdown to HTML. The program, called "Markdown," is available at the Daring Fireball website. NOTE: Markdown files also used the .MARKDOWN extension.