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),
Internet Explorer 4 98, in addition the Internet Explorer layout engine Trident was introduced. It attained just over 60% market share by March 1999 when IE5 was released. In August 2001 when Internet Explorer 6 was released, IE4.x had dropped to 7% market share and IE5 had increased to 80%. IE4 market share dropped under 1% by 2004. The Internet Explorer 4.0 Platform Preview was released in April 1997, and Platform Preview 2.0 in July that year. Internet Explorer 4 was released to the public in September, 1997 and deepened the level of integration between the web browser and the underlying operating system.