Jaspersoft Studio is an intuitive and powerful open source report designer for JasperReports. A full rewrite of iReport on top of Eclipse RCP and it is available as RCP application and as plugin for Eclipse IDE.
Jaspersoft Studio allows to create very sophisticated layouts containing charts, images, subreports, crosstabs and much more. Access your data through JDBC, JavaBeans, XML, Hibernate, CSV, and custom sources. Then publish your reports as PDF, RTF, XML, XLS, CSV, HTML, XHTML, text, DOCX, or OpenOffice.

Jaspersoft Studio
The standalone version can be downloaded here:
http://community.jaspersoft.com/project/jaspersoft-studio/releases
Reviews
solid report development environment
I have been using iReport for the past 5 years as my main report development tool for JasperReports. I was quite hesitant on switching to Jaspersoft Studio at first. As the Studio seems to be fairly complete and has matured over the past year I gave it another try, and frankly, I am impressed. All functionality I am familiar with is available in either a similar or better way, the UI is intuitive, the tool runs stable. After just a few days with Jaspersoft Studio I now consider retiring iReport and completely switching. The concept of data adapters, project workspaces and the ability to use it together with my java development environment just works out nicely. Well done!