Grid computing is the aggregation of networked computers to form a large-scale distributed system which can be used to solve complex scientific problems. The emergence of open standards has great influence on this computing technology, especially in providing seamless grid interoperability and grid integration facilities. This paper focuses on the need of interoperability between various grids and discusses TUX-INTERO, an interoperability system which is used to collaborate resources in a Grid using web services. It registers varied resources and makes them accessible to any end user.