Box2D is an extremely popular physics engine that has been ported to many languages. DartBox2D is the Dart port.
Rikulo Gap is a bridge implementation of the Apache Cordova mobile framework (a.k.a. PhoneGap) in Dart. It enables developers to access native facilities of multiple mobile platforms using the HTML, CSS, and Dart languages.
A PHP class for generating PDF documents.
Some chemistry-related programs for the GNOME desktop.