There are many applications build on JEE Application server that is based WebLogic.
Here I am sharing here few interesting links
Eclipse is favorite for most of JEE developers it is available with various flavours
Once you have Eclipse If you want to integrate it with WebLogic plug-in for deploying on server you can choose OEPE.
OEPE is fantastic tool for developing WLST scripts for configuring various JEE system resources such as JDBC, JMS, Clusters etc.
Best link I found for eclipse configuring