HTML4
HTML4 is the fourth major version of the HyperText Markup Language, released as a W3C Recommendation in 1997 and revised in 1999. It introduced significant improvements over HTML 3.2, including better support for style sheets (CSS), scripting, and internationalization, while deprecating older presentational elements in favor of separating structure from presentation. HTML4 laid the groundwork for modern web development by standardizing features like frames, forms, and accessibility attributes.
Developers should learn HTML4 primarily for historical context and maintaining legacy web systems, as it was widely used for over a decade and many older websites still rely on it. It's essential for understanding the evolution of web standards and for tasks like migrating or updating vintage web content to modern HTML5, where knowledge of deprecated elements and attributes is crucial. However, for new projects, HTML5 is recommended due to its enhanced features and better compatibility with current technologies.