Atom is available for a bunch of different platforms including Windows and Linux. The rpm package installs without error on Fedora 20 and 21. There is no binary package for FreeBSD, but there are instructions for building it from source both on that platform and OS X.
The software does come with a plugin that uses Google Analytics (metrics) to gather usage statistics, as well as a feedback (feedback)and bug reporting tool (exception-reporting). These can be disabled by going to Settings… Packages… Core Packages… and pressing the Disable button alongside each package you want to disable.