Markdown vs PHP: What are the differences?
Markdown: Text-to-HTML conversion tool/syntax for web writers, by John Gruber. Markdown is two things: (1) a plain text formatting syntax; and (2) a software tool, written in Perl, that converts the plain text formatting to HTML; PHP: A popular general-purpose scripting language that is especially suited to web development. Fast, flexible and pragmatic, PHP powers everything from your blog to the most popular websites in the world.
Markdown and PHP can be primarily classified as "Languages" tools.
"Easy formatting", "Widely adopted" and "Intuitive" are the key factors why developers consider Markdown; whereas "Large community", "Open source" and "Easy deployment" are the primary reasons why PHP is favored.
PHP is an open source tool with 23.9K GitHub stars and 5.53K GitHub forks. Here's a link to PHP's open source repository on GitHub.
9GAG, Hootsuite, and 37 Signals are some of the popular companies that use PHP, whereas Markdown is used by Asana, Code School, and GoSquared. PHP has a broader approval, being mentioned in 8904 company stacks & 2933 developers stacks; compared to Markdown, which is listed in 756 company stacks and 718 developer stacks.