The JasperReports Library is the world’s most popular Open Source reporting engine. It is entirely written in Java and it is able to use data coming from any kind of data source and produce pixel-perfect documents that can be viewed, printed or exported in a variety of document formats including HTML, PDF, Excel, OpenOffice and Word. More information at http://community.jaspersoft.com/.
iReport is the free, Open Source report designer for JasperReports and JasperReports Server. Create very sophisticated layouts containing charts, images, subreports, crosstabs and much more. Access your data through JDBC, TableModels, JavaBeans, XML, Hibernate, CSV, and custom sources. Then publish your reports as PDF, RTF, XML, XLS, CSV, HTML, XHTML, text, DOCX, or OpenOffice. More information at http://community.jaspersoft.com/project/ireport-designer.