I've been trying to find a library that will either let me display a .ppt file or an .odp file, but I've not really been able to find either so far. I've already tried the Apache POI library, but it only lets me display an image of the PowerPoint. If anybody has any suggestions of libraries I would greatly appreciate it.

If you just want to display the PPT or ODT file using the default application installed in windows then use the following command

File dest = new File("fileLocation\\fileName" + ".odp or .ppt");
Desktop.Action act;
act = Desktop.Action.OPEN;
Desktop desktop = Desktop.getDesktop();
desktop.open(dest);