JOrtho (Java Orthography) is a Open Source spell-checker entirely written in Java. Its dictionaries are based on the free Wiktionary project and can therefore be updated by virtually any language. The library works with any JTextComponent from the Swing framework. This includes JTextPane, JEditorPane and JTextArea.
Bizcal is a component library for calendar widgets written in java using swing. It has components for day view, week view, month view, group view, etc.