Synchronized Multimedia Integration Language (SMIL) is a World Wide Web Consortium recommended Extensible Markup Language (XML) markup language to describe multimedia presentations. It defines markup for timing, layout, animations, visual transitions, and media embedding, among other things. SMIL allows presenting media items such as text, images, video, audio, links to other SMIL presentations, and files from multiple web servers. SMIL markup is written in XML, and has similarities to HTML.
SMIL is a standard for interactive audiovisual presentations and is commonly used in mobile phones' MMS messaging. The abbreviation SMIL is read as "smile". A typical SMIL presentation consists of multiple "slides" playing in sequence.