Editors are for application development
There are many PostgreSQL development and administration tools available, and some are free. But pgEdit is the first editor optimized solely for PostgreSQL development. The typical PostgreSQL tool gives a big tree view of databases, schemas, tables, functions and so on (pgEdit will eventually have one too). This is fine for administration or simple development tasks, but gets in the way of developing complex database applications. The key issue is that an editor provides locality - you can group related tables, functions, triggers, and other database objects together in a file. As with other software development, you can build version controlled files of logically related objects rather than trying to work from a from a big tree view of objects listed by type and in alphabetical order.