Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.3.1. There are no new features with this version: Version 2.3.0 included a large amount of new code, and this version repairs several bugs from it.
Probably the most significant of these bugs is one that occurred when the user altered the attributes of a component so that it had more ports. Logisim would never forget the old ports, which would lead to problems with conflicting bit widths; this could only be repaired by closing and reopening the file - or by restarting Logisim. Thanks to the users who identified this bug and many others and submitted them anonymously to the bug tracker at SourceForge.
Educational institutions around the world use Logisim as an aid to teaching about digital logic and computer architecture. As a Java application, Logisim can run on most major operating systems. Read more about Logisim at http://www.cburch.com/logisim/, and download it from SourceForge.net at http://sourceforge.net/projects/circuit/.