The Commons Proper is dedicated to one principal goal: creating and maintaining reusable Java components. The Commons Proper is a place for collaboration and sharing, where developers from throughout the Apache community can work together on projects to be shared by the Apache projects and Apache users.
Commons developers will make an effort to ensure that their components have minimal dependencies on other libraries, so that these components can be deployed easily. In addition, Commons components will keep their interfaces as stable as possible, so that Apache users (including other Apache projects) can implement these components without having to worry about changes in the future.
This article gives an overview of (some of) the components which can be found here.
We welcome participation from all that are interested, at all skill levels. Coding, documentation and testing are all critical parts of the software development process. If you are interested in participating in any of these aspects, please join us!
One of the most commonly used set of general tools and utils. Some parts of commons library is a bit outdated while other parts are the best. My strategy for new projects is to add Guava and JodaTime and if I need anything else (e.g. simple HTTP Client) I look it up in Apache Commons.
Probably there isn't a Java project out there that doesn't use at least something from Apache Commons (if not directly, then at least indirectly as a transitive dependency).
Once this was one of the coolest libaries around and was the inspiration for many things that ended up in Java SE or Java EE, but lately innovation seems to have slowed down while that of e.g. Guave is still ramping up. Things like Commons Collections just aren't being updated anymore and without generic (Java 5) support it feels like a fossil from another age.
Still, there are a LOT of usefull goodies here.