Operating systems for reconfigurable computing (RCOS) facilitate the usage of Field Programmable Gate Arrays (FPGAs). RCOSes abstract from hardware details, utilise virtualisation, and provide standardised functionality. They allow different applications to run hardware tasks concurrently on the same FPGA by managing shared resources like FPGA area, I/O, and memory. Next to spatial partitioning, time multiplexed sharing of the FPGA can be reached via Dynamic Partial Reconfiguration (DPR). In this way, operating systems for reconfigurable computing support user applications to increase their performance and decrease energy consumption without the need to know the underlying concepts. Therefore, RCOSes pave the way for applications to exploit the advantages of FPGAs under consideration of their limitations like limited area and limited accessibility of configuration ports. Furthermore, RCOS can benefit from outsourcing parts of the OS into the FPGA. This survey outlines key concepts and gives an overview over state-of-the-art operating systems for reconfigurable computing. It points out general and specific limitations of RCOS. Finally, future trends are identified, which include a specialisation of RCOS with respect to their application's requirements like real-time processing, low energy consumption, reliability, safety, and security.