Drools API

The documentation concentrates upon the following key interfaces: org.drools.WorkingMemory org.drools.RuleBase org.drools.RuleBaseFactory org.drools.compiler.PackageBuilder org.drools.compiler.RuleBaseLoader org.drools.rule.Package These interfaces are fully intended to be exposed to application code.

See:
Description

Runtime Core API

org.drools
org.drools.rule	Contains the binary representations of rule constructs, like Package (which the compiler produces), Rule, and Conditional Elements.

Compiler Core API

org.drools.compiler

This is the main package to load rules.

Compiler Utilities

org.drools.lang	This contains the parser and utilities for the native DRL format, for handling DRL source.
org.drools.xml	This contains the parser and utilities for handling rules in XML format.

Runtime Utilities

org.drools.audit	This is a utility for providing audit trails/explanations of rule actions.
org.drools.event	Events provide all sorts of call backs to monitor the engine as it is running.
org.drools.visualize	Some visual utilities for viewing RETE networks (can also use the plug in for this)

Decision Tables

org.drools.decisiontable

This it a utility for using spreadsheets to manage rules.

Internal

org.drools.audit.event
org.drools.base
org.drools.base.evaluators
org.drools.common
org.drools.conflict
org.drools.decisiontable.model
org.drools.decisiontable.parser
org.drools.decisiontable.parser.csv
org.drools.decisiontable.parser.xls
org.drools.lang.descr
org.drools.lang.dsl
org.drools.lang.dsl.template
org.drools.leaps
org.drools.leaps.conflict
org.drools.leaps.util
org.drools.reteoo
org.drools.reteoo.beta
org.drools.semantics.java
org.drools.semantics.java.parser
org.drools.spi
org.drools.util
org.drools.util.asm
org.drools.util.concurrent.locks

Drools API

The documentation concentrates upon the following key interfaces:

org.drools.WorkingMemory

org.drools.RuleBase

org.drools.RuleBaseFactory

org.drools.compiler.PackageBuilder

org.drools.compiler.RuleBaseLoader

org.drools.rule.Package

These interfaces are fully intended to be exposed to application code. Gernally speaking, PackageBuilder would be used to assemble binary rule Packages, which are what is used by the core engine (RuleBase, WorkingMemory).

The other utility classes are optional, and you may or may not need to use them based on your specific needs.
The Internal APIs are not intended for "normal" application code use, but from time to time, advanced uses may need to refer to or use this API directly.