The vitality index indicates the degree of activity carried out in the last time period on each OSS Solution repository indexed in the Catalogue.

It reproduces exactly (in its definition and calculation) that envisaged by the guidelines on acquisition and reuse of software for Public Administrations defined by the Agency for Digital Italy - AGID, and currently officially implemented within the Developers.Italia OSS Solutions Catalogue.

This vitality index is calculated on the time window of the last 60 days (and updated once a week within this catalogue) taking into consideration the following four categories:

• Code activity: the number of commits and merges per day,
• Release history: the number of releases per day,
• User community: the number of unique authors,
• Longevity: the age of the project,

The ranges of each measurement can be found in the file vitality-ranges.yml.