Mobile Station Application Execution Environment (MexE) is a framework to ensure a predictable environment for third-party applications in GSM or UMTS handsets. MExE does this by defining different technology requirements called classmarks.
MExE classmark 1 is based on WAP, classmark 2 on PersonalJava and JavaPhone, and classmark 3 on J2ME CLDC and MIDP. Other classmarks may be defined in the future. MExE specifies additional requirements for all classmarks, for instance a security environment, capability and content negotiation, a user profile, user interface personalization, management of services and virtual home environment. A handset can support multiple classmarks. (Source: DeVx)