NeXTStep drivers were written in Objective-C using a framework called DriverKit, and this was on 90s machines. Objective-C is just C; there is no inherent perf

NeXTStep drivers were written in Objective-C using a framework called DriverKit, and this was on 90s machines. Objective-C is just C; there is no inherent performance penalty other than the dynamic dispatch of messages. In situations where that would actually be an issue, you'd be avoiding object-oriented features in C++ as well. However, driver performance bottlenecks are typically in I/O throughput, not the language the driver was compiled in. The fact OS X drivers are written in a C++ subset likely has to do with the demands of device manufacturers coming over from MacOS 9, just like the existence of Carbon was to appease application developers like Adobe.