The Java 101 series provides a self-guided introduction to Java programming, starting with the basics and covering all the core concepts you need to know to become a productive Java developer.

To celebrate Java’s 25th anniversary this year and the latest release of Java 15, JetBrains has compiled data from multiple sources to look at what the current state of the language is.

JetBrains is shipping version 9 of its IntelliJ Idea IDE for Java, this time offering both commercial and open source versions.