Arduino IDE for the 21st century.
This is a very early release version to allow people to try and see how it feels. There are many features missing - I know :)
apm install arduino-atom
Or install inside Atom.
This package is built on top of code written by Josh Marinacci in his ElectronIDE project.
Good catch. Let us know what about this package looks wrong to you, and we'll investigate right away.