Introduction.- Overview of DC Fault Protection Technologies.- ABB's Recent Advances in Solid-state Circuit Breakers.- Eaton's Recent Advances in Solid-state Circuit Breakers.- iBreaker: Intelligent Multi-mode Solid-state Circuit Breaker Technology Using Wide Bandgap Semiconductor Switches.- T-type Modular DC Circuit Breaker (T-breaker) for Future DC Networks.- Resonant Solid-state Breakers Based on Wireless Coupling in MVDC Systems.- ABB's Recent Advances in Hybrid Circuit Breakers.- Hybrid Circuit Breaker With Transient Commutation Current Injection.- Efficient DC Interrupter With Surge Protection.- 500kv/25ka Hybrid Circuit Breaker Development.- Hybrid Circuit Breaker Based on MMC Topology.- Ultra Fast Resonant DC Breaker.- Inline Gas Discharge Tube Breaker for Meshed MVDC Grids.- Converter-based Breakerless Protection.- Fault Current Limiters and Their Applications.- Fundamental Challenges and Future Outlook.