"A lot of people don't know that we have to maintain multiple code bases to maintain all of our mobile apps and websites. It was a giant pain." Erick Tseng, the company's head of mobile products, told Inside Facebook. The Facebook-tracking blog estimates about half Facebook users access the site on mobile via the Web and 60% through apps, suggesting some overlap between the modes. Tseng added that Facebook's mobile site overhaul pushes its overall mobile strategy toward HTML5, the programming language backed by other companies like Apple and Google for mobile content. Read more here.