The postgresql.conf comparison tool was created to make it easier to track changes to the database's main configuration file. These configuration options, referred to by the Pg hackers as GUCs ( Grand Unified Configuration), do change over time with major versions. These changes typically reflect new features added, existing features improved, and other changes.
This blog post illustrates how this tool can be used to research and prepare for upgrading PostgreSQL major versions.
Default configurations have been loaded for all major Postgres versions starting with 9.2. Configurations for new versions will be added as they are released. Older versions may be added as time permits.