HTML
Some might argue that by simply putting plain text in a file and saving it as .txt or .html, this simple text can be displayed in a browser. This might be true, but inserting plain text and loading it in a web browser is not similar as creating a web page. Without the right HTML tags, it is not actually a web page. If your end goal is to create a page from scratch and embed several string operations and many other things, HTML would remain the language for a bare minimum website.