On what standard is the geopackage (.gpkg) based?

The geopackage (.gpkg) format is based on SQLite, which is a relational database management system that stores data in a lightweight file format. SQLite is particularly suitable for mobile and embedded systems, and it supports transactional SQL queries, making it an ideal choice for managing geographic information in a compact and efficient manner.

The geopackage standard leverages SQLite's capabilities to not only store vector and raster data but also to facilitate the creation of a single, file-based container that can hold various types of geospatial data, ensuring data integrity and ease of use. This standardization allows for interoperability between different GIS applications, as the data can be easily read and written by compliant software.

In contrast, the other mentioned formats: XML Structure, Geographic Markup Language, and JSON Format, do not serve as the foundation for geopackage. While they are useful for representing geospatial data in different contexts, they lack the relational database component that SQLite provides within the geopackage framework.