There is now: https://www.voting.works/ Their system has been used in real elections in Mississippi, and they’re actively working to expand to other states.
> If anyone in government really wants to have a notable legacy, here's how: petition the USDS to create an integrated open-source election system, and get people like Matt Blaze and Harri Hursti to run a red team against it.
Check out the nonprofit VotingWorks, which is far along in already doing this: https://github.com/votingworks
For example, their system has been used in Mississippi in real elections.