Documentation / Packages and imports / Core packages
Core packages form small, typed packages owned by the compiler and selected for availability by a builder. They do not act as ordinary source files in your project, but they import with the same import syntax.
Most Core packages require explicit imports. The prelude keeps only the smallest always-available surface bare, such as io.
Builder support can vary. The progress matrix owns the source of truth for current package and backend support. The HTML builder currently supports optional core packages on the JavaScript path.