The Meteorological Data Explorer (METEX), developed by Jiye Zeng at the Centre for Global Environmental Research (CGER), includes programs for calculating air trajectory , for extracting meteorological data in various binary formats, and for plotting trajectory results and meteorological data. It can use datasets from European Center for Medium-Range Weather Forecast (ECMWF), National Centers for Environmental Prediction (NCEP), and Japan Meteorological Agency (JMA). Since these datasets can be downloaded freely and datasets of JMA and and NCEP are being disseminated in real time, METEX has been recognized as a useful tool for researchers of environmental studies.

The initial framework of METEX is to convert data in various formats to the Hierarchical Data Format (HDF) of the HDF Group so that application programs written for one dataset may be used with others. For more details, please refer to the CGER report "Data Analysis and Graphic Display System for Atmospheric Research Using PC".

The new version of METEX advances further to implement trajectory models in a Z-Script library and has implemented Z-Script interfaces for data input locally and SOAP interfaces for data input through network so that the trajectory calculation becomes completely data-source independent. That is that the new METEX offers two different methods of getting data for trajectory calculation: from local computer or from a data server through network.

This server provides services for online trajectory calculations, for viewing meteorological data, and for data and program download. It is also a data server: users may set the URL parameter of METEX program to http://db.cger.nies.go.jp/metex/soap/ to get data from the server for trajectory calculation.