A new multi-purpose LightWeight Grid system (LWG) is introduced, under the acronym CoBRA grid (Computational Basic Reprogrammable Adaptive grid). It provides the functionality grid users require, and offers grid developers the opportunity to test and alter grid components while the grid is in use. The grid was proven to operate properly by testing several applications and introducing new components. The performance is tested by the “sleep testing technique”, and a by implementing a quantum physics calculation. The user friendliness is also evaluated with the latter distributed computational problem. The possibility to port the system onto well established systems like CONDOR and GLOBUS is discussed.