This is the UI part of Eclipse's Java development tools, the user interface for the Java IDE. This includes views like Package Explorer and JUnit, the Java and properties files editors, Java search, and refactorings.
For more information and important links, refer to the JDT wiki page or the JDT project overview page.
Contributions are most welcome! There are many ways to contribute, from entering high quality bug reports, to contributing code or documentation changes.
Please bear in mind that this project is almost entirely developed by volunteers. If you do not provide the implementation yourself (or pay someone to do it for you), the bug might never get fixed. If it is a serious bug, other people than you might care enough to provide a fix.
Before your contribution can be accepted by the project, you need to create and electronically sign the Eclipse Foundation Contributor License Agreement (CLA).
Contact the project developers via the project's "dev" list.