Why do so many namespaces start with com
Why we keep seeing namespaces such as com.Apple or org.clojure
This is to maintain uniqueness among namespaces such as described by Oracle.
Companies use their reversed Internet domain name to begin their package names—for example, com.example.mypackage for a package named mypackage created by a programmer at example.com.
Name collisions that occur within a single company need to be handled by convention within that company, perhaps by including the region or the project name after the company name (for example, com.example.region.mypackage).
Packages in the Java language itself begin with java. or javax.