Just completed an update of the Atto Chemistry Editor and Computer Science plugins. Essentially, these just merge with the latest (Moodle 2.9) Atto Equation Editor JavaScript code. Should work with recent (2.7+) versions of Moodle.
Available from:
https://moodle.org/plugins/stats.php?plugin=atto_chemistry
https://moodle.org/plugins/stats.php?plugin=atto_computing
Or
https://github.com/geoffrowland/moodle-editor_atto-chemistry
https://github.com/geoffrowland/moodle-editor_atto-computing