Logisim is a circuit simulator, available here.

Logisim developers: Logisim uses the Gradle build system, so set that up first before attempting to develop Logisim. Ensure that the gradle executable is in the system path. To build the executable for Windows, you must install launch4j and ensure it is on the system path.

The build script recognizes the following commands:

gradle build     # Build application jar
gradle eclipse   # Build Eclipse configuration
gradle createExe # Build logisim executable
gradle run       # Run logisim from gradle