File created by Microsoft Visual Studio, a SDK for the Windows platform; contains compiled configuration data from a .CTC file for a VSPackage command set; resource for managed VSPackage code, native, or managed satellite DLL file; similar to a .CTSYM file.

The CTO file is created by compiling your CTC file using the Binary Command Table Compiler, which is the ctc.exe file. You can use your CTO and CTSYM file to create a .VSCT file: Place the CTO and CTSYM files in the same directory as the vsct.exe compiler. In the Visual Studio Command Prompt, navigate to the CTO and CTSYM file location. Type vsct.exe (ctofilename).cto (vsctfilename).vsct -S(symfilename).ctsym. Your VSCT file is now created and you can edit it using the VSCT Compiler.