Drools is available from two Subversion repositories.

To checkout drools source code just execute the following command.

fmeyer:~/jboss $ svn checkout http://anonsvn.labs.jboss.com/labs/jbossrules/trunk/ jbossrules

And wait to complete the files download.

A    jbossrules/drools-repository
A    jbossrules/drools-repository/.classpath
A    jbossrules/drools-repository/.project
A    jbossrules/drools-repository/doc
A    jbossrules/drools-repository/doc/repository_layout.jpeg
A    jbossrules/drools-repository/doc/high_level_design.jpeg
A    jbossrules/drools-repository/doc/javadoc
A    jbossrules/drools-repository/doc/javadoc/serialized-form.html
A    jbossrules/drools-repository/doc/javadoc/index-all.html
A    jbossrules/drools-repository/doc/javadoc/stylesheet.css
A    jbossrules/drools-repository/doc/javadoc/allclasses-frame.html
A    jbossrules/drools-repository/doc/javadoc/package-list
A    jbossrules/drools-repository/doc/javadoc/overview-tree.html
A    jbossrules/drools-repository/doc/javadoc/org
A    jbossrules/drools-repository/doc/javadoc/org/drools
A    jbossrules/drools-repository/doc/javadoc/org/drools/repository
A    jbossrules/drools-repository/doc/javadoc/org/drools/repository/class-use
A    jbossrules/drools-repository/doc/javadoc/org/drools/repository/class-use/RuleSet.html
A    jbossrules/drools-repository/doc/javadoc/org/drools/repository/class-use/RulesRepositoryException.html
A    jbossrules/drools-repository/doc/javadoc/org/drools/repository/class-use/RulesRepository.html
A    jbossrules/drools-repository/doc/javadoc/org/drools/repository/RuleSet.html

....

snip 

....

A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/benchmark/waltz
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/benchmark/waltz/waltz.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/benchmark/manners
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/benchmark/manners/manners.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/benchmark/waltzdb
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/benchmark/waltzdb/waltzdb.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/TroubleTicketWithDSL.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/TroubleTicket.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/conway
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/conway/calculate.rfm
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/conway/generation.rf
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/conway/calculate.rf
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/conway/registerNeighbor.rfm
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/conway/killAll.rfm
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/conway/registerNeighbor.rf
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/conway/conway-agendagroup.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/conway/killAll.rf
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/conway/conway-ruleflow.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/conway/generation.rfm
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/ticketing.dsl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/StateExampleUsingSalience.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/golf.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/LogicalAssertionsNotPingPong.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/StateExampleDynamicRule.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/sudoku
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/sudoku/sudoku.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/HelloWorld.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/ExamplePolicyPricing.xls
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/HonestPolitician.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/Fibonacci.drl
A    jbossrules/drools-examples/drools-examples-drl/src/main/rules/org/drools/examples/StateExampleUsingAgendGroup.drl
A    jbossrules/drools-examples/drools-examples-drl/pom.xml
A    jbossrules/drools-examples/drools-examples-drl/build.xml
 U   jbossrules
Checked out revision 13656.

Although, we highly recommend command line tools to work with repository you can also use both eclipse's integrated SVN client or TortoiseSVN

Setup TortoiseSVN to checkout from the subversion repository and click 'OK' Once the checkout has finished you should see the folders as shown below.