The Developmental Testbed Center (DTC) is a distributed center, located in Boulder, Colorado, with a mission to facilitate the transition between research and operation in numerical weather prediction (NWP). The two primary units of the DTC are the Joint Numerical Testbed of the Research Application Laboratory of NCAR and the Global Systems Division of NOAA's Earth Systems Research Laboratory. To fulfill its mission, the DTC focuses its efforts on two areas: (1) providing users support for the community NWP systems, and (2) performing testing and evaluation of community NWP systems to support research and operation. Currently, the DTC, in collaboration with the Messocale and Microscale Meteorology (MMM) Division of NCAR and the Environmental Modeling Center (EMC) of NCEP, provides support for the Weather Research and Forecasting (WRF) modeling system, the WRF for Hurricanes, the Grid-point Statistical Interpolation (GSI) data assimilation, and the Model Evaluation Tools (MET). The user support provided for all the systems includes annual tutorials, workshops, help-desk and documentations. Examples of testing and evaluations of community systems include the WRF reference configuration testing, and testing of WRF community repository code for operational hurricane prediction. In addition, the DTC also organizes special workshops on important challenges that are facing both the NWP community. Recent example includes the NWP Workshop on Model Physics with an Emphasis on Short-Range Prediction, held at NCEP/EMC in July 2011. The DTC also hosts a Visitor Program to facilitate the interaction between research and operational NWP communities. In this presentation, we will highlight results of recent testing and evaluation activities at the DTC with a focus on research to operation transition.