The JasperReports Library is the world’s most popular open-source reporting engine. It is entirely written in Java and can use data from any kind of data source to produce pixel-perfect documents that can be viewed, printed, or exported in a variety of document formats, including HTML, PDF, Excel, LibreOffice, and Word. More information at http://community.jaspersoft.com/.
iReport is the free, open-source report designer for JasperReports and JasperReports Server. It lets you 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 LibreOffice. More information at https://community.jaspersoft.com/.