jEdit is an Open Source programmer's text editor written in Java. It is
released under the GNU General Public License. jEdit was written for Java 1.1
with Swing 1.1, and also runs under Java 2.

As far as text editors written in Java go, jEdit is one of the best. It has an
easy to use, intuitive interface, and enough features and flexibility to please
even the most hard-core programmer. A very incomplete list of jEdit's features
follows.

o Syntax highlighting for 30+ file types (including C, C++, Java, Perl, etc) 
o Semi-intelligent auto indent in C, C++ and Java modes 
o Bracket highlighting and matching 
o Powerful macro system 
o Auto-expanding abbreviations for the frequiently used strings
o Powerful search and replace - supports regular expressions and multiple file
  search/replace; Search and replace operations can be recorded in macros 
o Any number of strings and caret positions can be stored for later use in
  so-called registers 
o Rectangular selections for working with column-based files
o Any number of editor windows can be opened, and each view can be split into
  multiple panes for side-by-side viewing of multiple files 
o Unlimited undo/redo 

WWW: http://jedit.sourceforge.net/