Atlassian, the parent company behind the Jira enterprise tracking and HipChat communication apps, on Monday announced a deal to acquire Trello, the developer of a cloud-based collaboration app for enterprise teams and personal use. Atlassian will fork over $425 million-- $360 million in cash and the rest in stock. Founded five years ago at the TechCrunch Disrupt conference in San Francisco, Trello provides software that includes digital whiteboards and virtual sticky notes to help customers collaborate on a wide range of projects.