GWTruts is an easy-to-use framework for using GWT with MVC and dependecy injection. It virtually divides a GWT module into view, controller, and validation sections similar to traditional MVC Web frameworks like Apache Struts. It also provides a dependency injection mechanism similar to Spring, which you can use to customize your controllers and views. It provides a page decorator where you can define mappings between a URL and a group of controllers/views and sections of the HTML files.
Compare Ikea Prices is a Firefox addon that displays prices from Ikea stores in other countries and converts the prices to Euros. It works for most Eurozone countries. After installing, it has to be turned on by checking an "Enable price comparing" checkbox in Tools > Compare Ikea prices.
ArchView can open archive files online without downloading the whole archive, just like normal Web pages. It is very fast since it just fetches a small portion of the archive file from the server. It supports RAR and ZIP formats, and HTTP, FTP, and file: protocols. It can present XUL or HTML interface.
gwt-hibernate provides the basics to create a web application that uses GWT on the front end and Hibernate on the back end. It provides code generation templates and support classes that allow introspection, data binding, and validation of POJOs in the browser. Data-bound Form and Grid widgets are included.
Pandorabots Chat Bot Interface is a learning tool for implementing AJAX to communicate between the browser and a server. The chat bot interface communicates via XML with a free chat bot you create and host at pandorabots.com. The client script controlls a div that records your ongoing conversation. The final product is an embedded chat bot in your Web site.