At the Voting Machine Village hosted at DEFCON this year, we'll see some extremely interesting projects on both the hardware and software sides.
DARPA are running three new smart ballot-box prototypes each based on a different processor architecture; with a view to promotion of hackers attempts at access; utilising an open-source hardware platform that has cross-purpose use both in future voting platforms and wider military projects. The team at DARPA are trying to make it as easy as possible to hack the prototypes - suggesting routes in, publishing hardware and software specifications and code - all with the aim of accelerating research; fail fast and fail early.
In a similar vein, Microsoft has built an open-source software platform called ElectionGuard - utilising encryption methods to verify vote authenticity and registration.
The area is absolutely ripe for development, after the first DEFCON Voting Village demonstration by Carsten Schuermann showed trivial in terms of difficulty (but fundamental in terms of impact) compromise of a popular voting platform based on Service-Pack 0 Windows XP, connected over WEP and with RDP enabled by default (not to mention, default, simple passwords for access) - well, it could hardly be worse...
DARPA to Bring its Smart Ballot Boxes to DEF CON for Hacking