One of the most significant changes in the WebLogic 12.1.3 release is improvements in the REST management interface. Oracle ACE Director and WebLogic expert Dr. Frank Munz does a very nice job summarizing the changes on his blog. The REST management capability is really quite a nice addition to the existing DevOps oriented capabilities such as WLST and of course the admin console. One of the very interesting things you can do via the REST management interface in WebLogic 12.1.3 is easily access all WebLogic logs. Dr. Frank Munz explains nicely step by step how to do this via another excellent blog entry well worth a read.
The best way to learn the details of the REST management capabilities is of course always the WebLogic documentation.