* Standard library source level compatibility with mostly preserved behaviour.
* Leveled logging with syslog levels.
* Structured key/value logging
* Hierarchical contextable logging to have k/v data in context logged automatically.
* Low resource usage to allow more (debug) log-statements even if they don't result in output.
* Light syntax to encourage logging on INFO/DEBUG level. (and low cost of doing so)
* Explore compatiblity with http://golang.org/x/net/context to make the context object a Logger.
* Flexibility in how log events are output.
* A fast simple lightweight default in systemd newdaemon style only outputting <level>message
  to standard output.