There is very little transparency in most electronic voting. (Optical scanners are the notable exception.)
However, a Seattle-area e-voting software firm announced this week that it was opening its source code to full inspection. The firm, Vote Here, also hired a third party to audit software performance. Both are unique actions in the world of electronic democracy.
Only one hardware manufacturer, Sequoia Voting Systems (Oakland, CA) has licensed the software, which provides an electronic audit trail.
Links: Wired (8 Apr); Seattle Times (7 Apr); VoteHere