What makes a successful system-on-a-chip (SoC)? The processor. What makes a successful software architecture? Development software. Without it, an operating system (OS) and application software just won't exist.
Few SoC CPU architectures are successful today, although each has a number of variants. Common among all are great development software tools.
So will anything make a dent in the big three: ARM, MIPS, and PowerPC? Customizable architectures, like those from Tensilica and ARC Cores, are one alternative. Java processors are another.
I like the idea of native Java processors. The embedded industry is leaning toward Java, especially in portable devices and gateway products. So why aren't Java processor cores rolling off the assembly line? Two reasons: the relative newness of Java for many developers and the good alternatives to getting Java without a Java processor. Software implementations of the Java Virtual Machine (JVM) are becoming more efficient, providing better performance on existing CPU architectures. Compilation to native code instead of Java Byte Codes (JBCs) allows performance that's comparable to application implementations in other languages like C.
Java accelerators are another alternative. Every major embedded CPU core has at least one Java accelerator option offering performance that's comparable to a native Java processor. The benefit is native code and JBC support.
Still, Java processors may have a new lease on life. Real-time Java standards make a standardized Java real-time operating system (RTOS) easier to build. Also, as more of an application is written in Java, the support for native code becomes less of an issue. Eventually, the overhead provided by the native processor architecture becomes a cost that gets harder to justify.
Java is slowly growing into performance-critical applications. Java processors and coprocessor cores are making this happen.
Existing processor cores will continue to be successful as long as C remains a major embedded development tool. In any case, successful SoCs will always need great development tools.