This article discusses some issues that a typical Windows C++ programmer will encounter when approaching Symbian OS for the first time. Our experience in developing for three successive versions of Symbian OS has given us considerable perspective on what can be difficult when working in this otherwise rich and stable environment. While one reason for Symbian s success may be the desire of many mobile phone manufacturers not to be tied to Microsoft, the other reason is that Symbian has put together a lightweight, elegant system that succeeds in providing a very impressive range of functionality. Here are some pointers to help ease the transition to successful Symbian OS application development.