There are two modes in weblogic : development and Production mode
Development mode
1) it comes with sun jDK
2) autodeployment is enabled
Production mode
1) it comes with Jrocket JVM
2) autodeployment is enabled
Jrocket has following advantages over sun JDK
1) Jrocket has better performance tracking tools with no overhead on the performance
2) It uses higher memory for performnace reason. it uses higher memory as the machine code translated from java byte code is saved in the memory for avoiding the translation again and again.
3) JRockit does not have an interpretation mode, compilation only, so due to its additional native memory needs the process size tends to use a couple of hundred MB larger