The document summarizes lessons learned from Alcatel-Lucent's experiences with implementing a social intranet called Engage. It discusses how Engage was introduced to address limitations of traditional collaboration tools and better connect the company's global workforce. Key findings include that social media can unleash new models of in-company communication and collaboration by breaking down organizational boundaries. Building active communities requires identifying a purpose, recruiting champions, and nurturing early adopters. Ongoing community growth depends on monitoring, celebrating successes, and persistence over time.