The natural log appender!
This extremely lightweight JavaScript logging library was written mostly for fun, but also for serving the purpose of providing a logger which doesn't break a script if the console object doesn't exist for some reason!
Initialise a logger with
var logger = new Logger(); // Logger('warn') would return one with a level of WARN
Set log level with a string representation
logger.setLevel('info');
Get the value of Euler's constant
logger.e
Enjoy!