WLST (WebLogic Scripting Tool) is one of the many WebLogic features that ease the management and administration of WLS instances. It is a command line based tool that can be used to create, manage, and monitor WebLogic domains.  WLST has a set of WLS specific commands (e.g. deploy an application – see here for the whole commands list), so creating WLS automated tasks is really easy. And since WLST is running on the JVM (*), those various scripted WLS taks can be easily integrated in the overall infrastructure (e.g. build platform, management infrastructure).

Mark Piller has recently written an technical introduction to WLST. In his article, Mark explains how to write WLST scripts.

You can also watch this WLST tutorial video produced by Frank Munz.

(*) Technically, WLST is using Jython on top of the JVM.