As far as I can tell (in December 2013) ...

• Douglas Crockford's master source repository for "json.org" is now on GitHub - https://github.com/douglascrockford/JSON-java. (The GIT history starts in 2010, and the latest change in "master" is a couple of weeks ago.)

• Paul Merlin (aka "eskatos") has Mavenized the code: https://github.com/eskatos/org.json-java

• Binary "org.json" JAR files are "regularly" built from Paul Merlin's tree and pushed to Maven Central. You can find them via the "here" link in Paul's README.md file; see the line above.

• There are other older (pre-2010) binary releases of the "org.json" JAR file in Maven Central under various guises; review the search results for this link" http://mvnrepository.com/search.html?query=org.json.

The copyright dates in the "org.json" source code don't mean much. They clearly aren't updated when the code is updated. However, Douglas Crockford does update the @version javadoc tags, at least in some commits.

UPDATE (December 2016)

As of some time in 2015, Douglas Crockford has passed ownership of the Github repository to Sean Leary. The old Github URL for the project now redirects to https://github.com/stleary/JSON-java. The project continues to be relatively active.

See also: Where has json.org java library gone?

Have you considered using Maven? for instance, if you wanted a JAR to pars JSON you could just include...

http://mvnrepository.com/artifact/org.codehaus.jackson/jackson-core-asl/1.9.6

<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-core-asl</artifactId>
    <version>1.9.6</version>
</dependency>

in a pom.xml, this will give you the jar for JSON.

Or better yet, use the org.json one...

http://mvnrepository.com/artifact/org.json/json

<dependency>
    <groupId>org.json</groupId>
    <artifactId>json</artifactId>
    <version>20090211</version>
</dependency>