The 2.7.1 version of Logisim is provided as a free download on our website. The program is categorized as Education Tools. The actual developer of the free software is Carl Burch, Hendrix College.
From the developer:
Logisim is an educational tool for designing and simulating digital logic circuits.
You may want to check out more software, such as Colors, CCNA CertSim or Professor Teaches Windows XP Professional, which might be related to Logisim.