Is there some reason that open source is better?<p>Even open source software is opaque. You can't know that the software is unaltered when it's running on a machine. If that machine does something other than produce and print a paper ballot and provide a preliminary count, I'd say something is wrong. And if a closed-source machine prints the wrong ballot, it's for the voter to verify and object. Open source doesn't change that.<p>Open source seems to be an argument only if you want to have direct counting without an audit trail. If that's the case, the open source aspect is just obfuscating that the overall system is broken.