FirmaSAT has been helping users sign and analyze CFD and CFDi Comprobante documents since 2007. See a full list of features.
FirmaSAT is a fast, stand-alone product that does not use any slow external XML or crypto libraries. In particular, FirmaSAT does not use OpenSSL in any form. FirmaSAT runs on all modern versions of Windows (XP and above). A custom version for i386 Linux can be made available on request.
You can run FirmaSAT from the command-line, or call it using the "system" command of another program (for example, using ColdFusion or SQL Server), or call its underlying functions and methods using one of many programming language interfaces, including Visual Basic, VBA and C#.