There is only one language which has been hot in the IT industry for more than 20 years. End of this year, Java turns 30. Thanks to James Gosling and Congratulations to Java!
Any history of Java would need to reference Stealth, Green, Oak and C++. They point to their founding as an attempt to be unshackled from conventional developer environments.
Java is most popular because of the portable developer environment with the famous tagline promise of Write Once, Run Anywhere. Later they introduced distributed server side architecture components, Java EE.
Java became highly important on the server side and today it remains a popular environment to solve practical computing challenges where systems can talk to each other.
Another important feature introduced during the birth of Java is Java Media API. Nowadays, most of the apps are using alexa voice and google talk, however the initiator is Java.
When Oracle bought Sun Microsystems in 2009 there was fear in the Java community, but Java is still hot in modern server environments. Oracle cites CERN, NASA, Twitter, Netflix and Minecraft use cases are examples of its elasticity.