- #2 - Stack Exchange
Launched in 2010, the Stack Exchange network comprises 173 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Since then, the Stack Exchange network has grown into a top 50 online destination with Stack Overflow alone serving more than 50 million developers every month. Stack Overflow also partners with organizations that seek to leverage technology to innovate. Our products and services are focused on enterprise knowledge sharing, technical recruiting, and advertising.