log15

Encourages key/value pairs for machine-readable logs, as shown in examples where log messages include context like 'rate=0.500' and 'module=app/server'.

Simple Handler interface allows custom configurations to files, streams, syslog, and networks, demonstrated by MultiHandler and FileHandler in the examples section.

Child loggers enable modular logging by inheriting and adding private context, useful in microservices, as seen with 'connlog := srvlog.New("raddr", c.RemoteAddr())'.

Defers expensive operations until necessary, improving performance, shown with 'log.Lazy{pingRemote}' for deferred latency calculation.