Also some Apache Java libraries (several of which are used in Android)
Some of them are a bit odd:
http://projects.apache.org/projects/commons_chain.html
Others have really, really buzzwordy descriptions:
I guess it depends what you're comparing to, but I think of Java projects as more monolithic. Spring does dozens of different things compared to something like say Flask. And particularly in Haskell or Javascript you seem to need 100 tiny libraries to do anything.
Does it have its own subdomain on apache.org? Then it's a top-level project.
It's not uncommon for projects to start as subprojects and then get upgraded to the top level, and some of them came out of Hadoop. For example, Avro started out as a Hadoop subproject before becoming its own top-level project.