As a feasible solution to ensuring both driving efficiency and passing ability, wheel-legged robots have become increasingly popular in robotics research community. This paper introduces an open source mobile manipulator with wheel-legged locomotion - the ARX 6, which is dedicated to robotic research and education. Firstly, tailored mechanical design guarantees agile manipulation and multi-terrain mobility with simple dynamic control models. Secondly, our software framework supports deploying algorithms in the real-time simulation and the real world simultaneously, which greatly improves the sim-to-real adaption efficiency. Lastly, the hardware capability and the software compatibility are demonstrated by diversified field experiments including fundamental motion control, multi-terrain navigation, mobile manipulation, and lowspeed autonomous driving. These results collectively represent a ready-to-use mobile manipulation platform capable of conducting generalized research and education with a dynamic leg-wheeled locomotion.