I used to use log4j because it was most popular, but recently decided to try JDK logger in my current project. I like that it is built into the JDK so there are no .jar dependencies, version conflicts, etc. All I need it to do is write to a disk file using a format String I specify, rotate logs after x KB, and to keep only y archived files. I'm just as satisfied with it as I was with log4j.
A while ago I did some reading about the history of logging frameworks to try and understand the hostility many developers still have towards JDK logger. From what I can tell log4j was the first widely popular logging framework in Java. Later, its ideas and general API design were standardized in JDK 1.4. The names of some things were changed, but the concepts are the same. There were many developers who did not want to require "the new" Java 1.4 so they continued with log4j. Later the commons-logging wrapper was created to provide libraries and applications the ability to use either log4j or JDK logger depending on what is present in the environment. Even today with the pending release of Java 1.7 many developers use log4j or commons-logging instead of the built in JDK logger.
My question to you is what is wrong with the JDK logger? Why do some people say it was disaster? Why don't you use it? I am not trying to start a flamewar, I am genuinely interested. Is it because log4j comes with many more built-in appenders such as NTEventLogAppender, JMSAppender, and SMTPAppender? I figure the JDK logger has only basic core handlers/appenders for the same reason JSF comes only with basic HTML UI components.