The following sections describe several useful alternative development environments for the Palm OS.
There are two different full Java environments, as well as two Java-like environments. Keep in mind, however, that there is a definite overhead to using Java (interpreters and garbage collection take time, virtual machines take storage space).
Sun’s approach to Java is to provide a way to write Java applications that will run across multiple platforms. Since the Java 2, Standard Edition is too large to run on small devices like those running the Palm OS, Sun has defined Java 2, Micro Edition (J2ME), a subset of the standard edition with new class libraries.
Sun has defined configurations : APIs targeted at classes of devices with related characteristics and limitations (memory, speed, and so on). The configuration for Palm devices is the Connected Limited Device Configuration (CLDC), which targets devices like PDAs, cell phones, and two-way pagers.
There are also profiles , which are more specific. There are two profiles of interest for Palm OS devices: the PDA profile (which, at the time of this writing, was not yet defined) and the Mobile Information Device Profile (MIDP). MIDP applications are called “MIDlets” and can run on any CLDC configuration with the MIDP profile.
Sun has a version of the CLDC configuration and MIDP APIs for the Palm OS at http://java.sun.com/products/midp/palmOS.html.