Logisim is an application for designing and simulating logic circuits. It is used by college students studying computer organization or logic. Logisim files have the .circ extension. These XML formatted files contain circuit data like names and locations of gates and wiring. As of October 2014, Logisim development has been indefinitely suspended.
The .circ file extension is associated with the Windows platform. It falls under the Misc Files category, which has over 6,000 file types. Logisim is the most common program to open .circ files. The official Logisim website provides detailed information on .circ and supported formats.
If a system cannot open a .circ file, it likely means no installed programs support that file type. To open an unsupported .circ file, try installing Logisim or another program handling circuit design files and XML formats. Viewing the .circ file content in a text or source code editor is another option.
Logisim