Android (operating system) and rival Linux mobile operating systems that were in development. These established players were skeptical: Nokia was quoted as saying "we don't see this as a threat," and a member of Microsoft's Windows Mobile team stated "I don't understand the impact that they are going to have." Since then Android has grown to become the most widely used smartphone operating system and "one of the fastest mobile experiences available". Reviewers have highlighted the open-source nature of the operating system as one of its defining strengths, allowing companies such as Nokia (Nokia X family), Amazon (Kindle Fire), Barnes & Noble (Nook),
Copland (operating system) its window. Programs that are not in the foreground are periodically given short bits of time to run, but as before, the entire process is controlled by the applications, not the operating system. Because the operating system and applications all share a single memory space, it is possible for a bug in any one of them to corrupt the entire operating system, and crash the machine. This is not particularly annoying under a single-application model, in which case the application crashes anyway. But under MultiFinder, any crash will crash all the other running programs as well. The multitasking of multiple