There are two source roots at present:

/src - Source to include in a distribution lives under here
/test - For unit tests; the hierarchy should parallel /src

Please use only the libideas and widgetideas package hierarchies,
organized with typical GWT organizational conventions. 

We are well aware that having many developers work in a small 
number of packages invites collisions. That is intentional.  
We don't want many different people working on slightly different versions 
of the same thing in a way that will be unlikely to converge, thus turning 
this project into a dumping ground. Instead, we want to force the issue of 
"what if I'm trying to create the same widget that someone else is already 
working on" so that the path of least resistance will (hopefully) be to 
join forces to work on a single great implementation.

=== Widget packages ===
com.google.gwt.widgetideas
- root package for all things visual, typically widgets
- add module XML here

com.google.gwt.widgetideas.client
- actual widget code lives here; please don't create additional subpackages

com.google.gwt.widgetideas.client.impl
- contains deferred binding sublcasses and other low-level implementation

com.google.gwt.widgetideas.rebind
- contains deferred binding generators related to widgets

com.google.gwt.widgetideas.server
- contains server-side support related to widgets

=== Library packages ===
com.google.gwt.libideas  
- root package for all things non-visual
- add module XML here

com.google.gwt.libideas.client
- actual library code lives here; please don't create additional subpackages

com.google.gwt.libideas.client.impl
- contains deferred binding sublcasses and other low-level implementation

com.google.gwt.libideas.linker
- contains build-time support related to linkers

com.google.gwt.libideas.rebind
- contains deferred binding generators related to libraries

com.google.gwt.libideas.server
- contains server-side support related to libraries

Happy coding.