Grid environments, providing distributed infrastructures, computing resources and data storage, usually show a high degree of heterogeneity in their metadata. We propose a platform for collaborative management and maintenance of common metadata for grids. As the conceptual foundation of this platform, a meta model is presented which distinguishes structured descriptions and classification structures. On this basis, the system allows for the user-friendly creation and editing of grid relevant metadata and provides various search and navigation facilities for grid participants. We applied the platform to the German D-Grid initiative by establishing the D-Grid Ontology (DGO).