E-voting has been successfully used 5 times in Estonia since 2007. It facilitates national ID cards which are obligatory for all citizens. In the next municipal elections later this year it is planned to test an experimental feature where the voter can check via a physically separate channel (smart phone) if his or her vote has been registered correctly.
The original in Estonian: http://www.postimees.ee/1297368/e-haaletamise-tarkvara-lahtekood-sai-avalikuks
The publicized source code: https://github.com/vvk-ehk/evalimine"