[digg-reddit-me] Google Guice is a an open source Java framework released by Google under Apache License 2.0. Guice is a light weight Inversion of Control Container. It does what Spring does regarding dependency inversion aspect, without using xml files. Guide uses annotations and requires Java 1.5 or above and follows the Google philosophy of being really easy to use.
Skipping the technical aspect, I can not ignore a few points.
Google releases a Java framework, produced in their free open source code forge, aiming a "market" where there is only one "competitor", Spring, the only Java IOC Container truly widely used. Guice is not a real Google product, it is resulted from their initiative to support the open source community. The interesting aspect here is the fact that the owner of the project is Google itself, Guice is not only an open source framework hosted on Google Code.
Spring is a framework used to integrate any other framework. Guice is intended to be the same. Entire web and enterprise applications can be built on it. It's something that everyone needs.
Guice is more close to the conventional applications, it is not an MashUp Api and is not based on google products like most of the api's made available for the masses, it's a framework than can be used for any Java application. In other words Google expands its boundaries toward a more traditional software community.
Guice seems to be really nice and light and many programmers prefer using it, writing java code instead of changing xml files in Spring. You can check the google tech talks presentation on google video: