The Mobile Execution Environment (MExE) is a functionally enhanced WAP technology based on Java. MExE is part of the specifications of 3GPP and defines a flexible and secure application environment for mobile GSM and UMTS phones or PDAs. It has more features than the Wireless Application Protocol (WAP) and also has more application possibilities.
There are different MExE versions:
MExE Class Mark3 supports Java applications and is based on Java 2 Micro Edition( J2ME).
MExE Class Mark 4 is based on Common Language Infrastructure - Compact Profile(CLICP). It can be used with many mobile devices and various programming languages.