layout home hero name tagline actions Scratch Specification A detailed explanation of how Scratch 3.0 works. WIP. This is in early stages and not yet complete. theme text link brand Introduction /intro/ theme text link alt Quickstart /intro/#where-to-start theme text link alt FAQ /intro/#faq features title link details Introduction /intro/ An explanation of what this spec is trying to achieve. title link details Ideas /concepts/ Formal definitions for basic Scratch concepts. title link details Runtime /runtime/ How scripts run. title link details Palette /palette/ Every. Block. Ever. title link details File Format /files/ The file formats used to save projects and load them as Scratch runtime objects. title link details Input / Output /io/ How Scratch receives inputs, renders images, and plays sounds. title link details Cloud Networking /network/ How Scratch handles requests to external servers, as well as cloud variable manipulation. title link details Scratch Link /devices/ How Scratch interacts with programmable hardware components.