Clarizen is hot startup with a fantastic survival story. Today it’s growing like mad and on an IPO track. But there was a time when it was hanging on for life, co-founder and CEO Avinoam Nowogrodski told Business Insider. Founded in 2006, Clarizen has 2,000 enterprise customers worldwide and is growing like crazy. It offers a project management tool that marries social (e-mail, chat) with task management. It competes with tools like Asana and Microsoft Project.