One of the main goals of the international project, called HP-SEE, is to achieve the interoperability between remote supercomputers using the ARC-AREX middleware. This program package that is accepted in many countries from Finland till Switzerland is developed by Nordugrid community to be able execute and manage applications on remote and distributed systems. In parallel research communities in other countries of Europe are supported by an other, EGEE-provided middleware called gLite. Nowadays these two main, most common middlewares are stable enough to develop a higher-level software component what provides the interoperability between gLite and ARC.

This higher-level component means portal solutions, in our case it's gUSE, a popular web-based grid application development framework developed by MTA SZTAKI. Besides that this system provides accessibility to remote and distributed resources in a user-friendly way, it contains a development system, where the users can create a parallelized version of their application. This abstract program is represented by a workflow in the portal, and the components of it are represented by jobs. The main advantage of gUSE portal is that the execution on the supported middlewares are provided in workflow-level, which means that besides more grids, therefore more resources can be accessed by the researchers, these can be accessed within one workflow (each job can be submitted into different grid system).

As a result of the development other research groups and communities can use grid systems via a simple web-browser, on the other hand users, who has certificate for both grids, can use larger set of resources.

The presentation introduces the ARC and gLite middleware in draft, excepting similarities and the differencies of them, shows the general services, and the architectural solution of gUSE portal. Then shows the main milestones of the middleware-plugin development; the revealed problems, and solutions of them; the integration steps of the new extension; finally it shows the test results.