Large-area particle detectors based on the bulk-micromegas technology are an attractive option for the upgrade of LHC detectors and/or detectors for the ILC or other experiments. In the context of the R&D for the ATLAS Muon System upgrade, we have built and tested detectors of order 1 m2. In order to overcome the spark problem in micromegas, a novel protection scheme using resistive strips above the readout electrode has been developed. This technology has undergone extensive tests with high-energy hadron, MeV neutrons, and keV photons. In addition a few small prototype chambers have been installed in the ATLAS cavern and are taking data under LHC conditions. We will discuss the underlying design of the chambers, present results on their performance, and address issues still to be studied before going into mass-production.