HTML - Hypertext Markup Language, CSS - Cascading Style Sheets

HTML and CSS are the building blocks of web pages.

HTML and CSS Validation

Having valid HTML and CSS is important in ensuring that your pages are accessible to all users and compatible with all browsers. Here’s a list of useful and free validators:

Links

• W3C CSS Validator
• W3C Link Checker
• Total validator

MathJax

MathJax is a JavaScript display engine that can render math formulas in HTML.