The state of Wisconsin has passed a law requiring that all software used in voting machines be open and accessible to the public. This is the right thing to do. Voting is the bedrock of a democratic republic, and how votes are tallied cannot be held close by a private company.
Voting software that is open to inspection by third party experts will be more secure and more robust than "secret" code. This approach has already been show to yield excellent results; in general, open source software like Linux, which has a worldwide group of programmers examining the code, has fewer bugs and security issues than private code like Windows.
What is unfortunate is that most electronic voting machines, most of which are less than a year old, will have to be upgraded or replaced in the next couple of years. Public officials and voting registrars failed to do their duty when purchasing these machines. A broad array of programmers and security experts warned repeatedly that the current crop of machines (two companies have captured most of the market) are insecure and vulnerable to vote-changing. The recent demonstration that votes in Diebold machines can be easily altered (North Carolina) was a wake up call to legislators.