The Apache POI Project is a Java APIs for manipulating various file formats based upon the Office Open XML standards (OOXML) and Microsoft's OLE 2 Compound Document format (OLE2). In short, you can read and write MS Excel, Word, and Powerpoint files using Java.

Apache POI became a top level project in June 2007 and POI 3.0 artifacts were re-released. Prior to that date POI was a sub-project of Apache Jakarta.