Too Long; Didn't Read
More than 4 billion people access the web through combinations of - 9000+ distinct devices, shipped with 21 different operating systems (vendor + version) and 8 major browser engines that power hundreds of browsers. They make at least 63,000 possible browser-platform-device combinations. Fragmentation is the inability to "write once and run anywhere’s a problem in development,’ says Damith Rajapakse. Fragmentation becomes a bigger problem with every new mobile or desktop device, but also with the bigger problem in fragmentation in operating systems.