Screaming Penguin - Source Does Matter

It's "less crashy" on Linux (gotta love the honesty).

http://www.screaming-penguin.com/docs/gwt-1.4.59/

Highlights from the release notes:

DOM.eventGetCurrentEvent() now provides global access to the current Event object. (#1309)

RPC now generates a serialization policy file during compilation. The serialization policy file contains a whitelist of allowed types which may be serialized. Its name is a strong hash name followed by .gwt.rpc. This file must be deployed to your web server as a public resource, accessible from a RemoteServiceServlet via ServletContext.getResource(). If it is not deployed properly, RPC will run in 1.3.3 compatibility mode and refuse to serialize types implementing Serializable. (#1297)

Panel.adopt(Widget, Element) and Panel.disown(Widget) have been deprecated. If you have subclassed Panel, please carefully review the new documentation for Panel.add(Widget) and Panel.remove(Widget) for details on the correct way to add and remove Widgets from Panels. (#1121)