Sun is calling out Apple for it’s decision to leave Java off of the iPhone. Apple’s stance was called a mistake by a Sun Microsystems executive Wednesday at the AJAXWorld conference in Santa Clara.

“I think it’s a mistake. I think it would provide a lot more flexibility in applications being developed,” for the iPhone, said Bob Brewin, Sun Distingushied Engineer and vice president for software. By not having it on there now, iPhone users and Java developers are being shortchanged, according to Brewin.

Brewin’s criticism reflects Apple’s approach to the iPhone, treating it more like an appliance than a platform that can be built upon. “Fundamentally, they don’t like open systems,” Brewin said.

In addition to Java support, Apple crippled its Web browser, Safari, removing Flash support, and has made other efforts to keep developers from treating the iPhone as a platform. While Apple encourages development of Internet apps for the iPhone, this limits they types of apps that can be created.