I'm not sure what you mean by "commercial use". The JVM is inherently multi-threaded - where there's a JVM, there are multiple threads.
Servlet containers and JEE servers are multi-threaded with respect to handling simultaneous requests, so wherever there is a web site based on servlets/JSP (or using EJBs in the background), multi-threading is going on. Look for URLs like "*.jsp", *.do" and "...servlet..." - those generally indicate that a site runs on Java.
posted 7 years ago
Even before you start a thread with thread.start() there is a thread for running main(). Also the Java Runtime will have created other threads, such as garbage collection thread. So threads are ubiquitous.
Rajeev Trikha (SCJP 6)
Let's go to the waterfront with this tiny ad:
the new thread boost feature: great for the advertiser and smooth for the coderanch user