"According to Novell's lead Mono developer, Miguel de Icaza,
several applications in Apple's App Store are powered by Mono. This
might come as a bit of a surprise to those familiar with Apple's
highly restrictive application inclusion policies, because the
company strictly prohibits developers from using interpreted
languages and third-party runtime environments--a constraint that
largely rules out technologies like .NET and Java.
"Static compilation is the special sauce that makes it possible
for Mono to run on the iPhone. Mono allows developers to use
ahead-of-time (AOT) compilation, which converts .NET's common
intermediate language (CIL) directly to native code at compile
time. This means that the application doesn't have to use
just-in-time (JIT) compilation to generate the native code at
runtime."