Do I need to use all the Closure tools in my project?
While the Closure tools work well with each other, they can also be used individually in a project. For example, you can use the Closure Compiler to compile your existing JavaScript code without using any of the other tools.
How do the Closure Tools relate to Google Web Toolkit?
Google Web Toolkit (GWT) provides a development tool chain for building and optimizing complex web applications, and is used in products like Google Wave and AdWords. Closure is a set of individual JavaScript tools that are also designed to help developers build complex web applications, and is used by Gmail, Google Maps, and Google Docs.
Closure is geared toward developers who want to work with JavaScript and have a strong understanding of the language, while GWT allows developers to work primarily in Java (although they can work in JavaScript, too) without worrying about the underlying JavaScript.
How do the Closure Tools relate to Doctype?
Doctype is a reference and documentation project released by Google. A subset of the full Closure Library was open sourced with Doctype for use in examples.
May I use the Closure logo or name in my project?
The Closure Tools trademark and associated logo are owned by Google Inc. Though the Closure Tools source code is offered under the Apache License, Version 2.0, this license does not grant unrestricted permission to use the name or logo (see the license).
The Closure Tools trademark and logo may be used to identify the Closure Tools suite or any of the properties in the suite in a reasonable, customary, fair-use manner. Examples of use include documentation or articles written about Closure or instructions for how to use the tools in practice.
The Closure Tools trademark and logo may not be used in connection with an independent product or project name, or in any way that would imply that an offering is part of or otherwise related to the Closure suite.