The dominant mobile operating systems at the time such as Symbian, BlackBerry OS, and Windows Mobile were not designed to handle tasks beyond communication and basic functions. These operating systems never focused on applications and developers, and due to infighting among manufacturers as well as the complexity of developing on their low-memory hardware, they never developed a thriving ecosystem like Apple's App Store or Android's Google Play. iPhone OS (renamed iOS in 2010) was designed with capabilities such as multitasking and graphics to meet future consumer demands. Many services were provided by mobile carriers, who often extensively customized devices. Meanwhile, Apple's decision to base its OS on OS X had the unexpected benefit of allowing OS X developers to rapidly expand into iOS development. Rival manufacturers have been forced to spend more on software and development costs to catch up to the iPhone. The iPhone's success has led to a decline in sales of high-end fashion phones and business-oriented smartphones such as Vertu and BlackBerry, as well as Nokia. Nokia realised the limitations of its operating system Symbian and attempted to develop a more advanced system, Maemo, without success. It ultimately agreed to a technology-sharing deal and then a takeover from Microsoft.