Java

What is Java?

Java is a general-purpose, object-oriented programming language together with the runtime environment that executes it. Developers compile Java source code into bytecode, which runs on a Java Virtual Machine (JVM) that translates it into instructions for the underlying hardware. Because JVMs exist for every major operating system, the same compiled program can run on Windows, macOS and Linux, the idea behind Sun Microsystems’ “write once, run anywhere” slogan.

The platform ships with a large standard library for networking, concurrency, collections, security and database access, and the JVM manages memory automatically through garbage collection while its just-in-time compiler optimizes frequently used code as a program runs. That mix of portability, tooling and performance made Java a default choice for enterprise back-end systems. Frameworks such as Spring and data tools such as Apache Kafka, Apache Hadoop and Elasticsearch are built on the JVM, and other languages, including Kotlin, Scala and Clojure, compile to JVM bytecode too.

Oracle leads Java’s development through the OpenJDK open-source project, and new feature releases arrive every March and September. Every fourth release, most recently Java 25 in September 2025, is a long-term support version that Oracle and other vendors such as Microsoft, Amazon, Red Hat and Azul maintain with years of updates. Java 27 reached general availability on September 15, 2026, turning on compact object headers by default and adding post-quantum hybrid key exchange for TLS 1.3.

Key features of Java

1. 01

   Java Virtual Machine

   The JVM loads and verifies compiled bytecode, manages memory and uses just-in-time compilation to optimize frequently executed code, which lets the same program run efficiently on different operating systems and processors.

2. 02

   Automatic garbage collection

   Collectors such as G1, ZGC and Shenandoah reclaim unused memory automatically, sparing developers manual memory management, and low-pause collectors keep interruptions short even on very large heaps.

3. 03

   Extensive standard library

   The Java class library covers collections, file and network I/O, an HTTP client, concurrency utilities, cryptography, date and time handling, and database connectivity through JDBC.

4. 04

   Virtual threads

   Finalized in Java 21, virtual threads are lightweight threads managed by the JVM rather than the operating system, letting servers handle very large numbers of concurrent tasks with simple blocking code.

5. 05

   Modern language features

   Recent releases added records, sealed classes, pattern matching for switch and instanceof, text blocks and local-variable type inference, cutting much of the boilerplate older Java code required.

6. 06

   Predictable release cadence

   Feature releases ship every six months, and a long-term support release arrives every two years, giving organizations a choice between the newest features and a stable version maintained for many years.

7. 07

   Large tool and framework ecosystem

   Build tools such as Maven and Gradle, IDEs such as IntelliJ IDEA and Eclipse, and frameworks such as Spring Boot, Quarkus and Jakarta EE support Java development from prototypes to large systems.

Who uses Java?

• Banks, insurers and retailers build transaction processing systems and web services with Java frameworks such as Spring Boot and Jakarta EE.
• Android developers write apps in Java, although Google has recommended Kotlin as its preferred Android language since 2019.
• Data engineering teams run JVM-based big data and streaming tools such as Apache Kafka, Apache Hadoop and Elasticsearch.
• Universities and high schools teach object-oriented programming with Java, which is the language of the AP Computer Science A course in the United States.
• Smart card and SIM makers use Java Card, a compact Java variant, to run small applications securely on chips.

History of Java

Java began in 1991 as the Green Project, a Sun Microsystems effort led by James Gosling to write software for consumer electronics such as interactive television. The language was first called Oak and was renamed Java before Sun announced it in May 1995. Its arrival coincided with the early web, when Java applets let small programs run inside browsers such as Netscape Navigator, and JDK 1.0 followed in January 1996.

Sun released Java’s source code under the GPL in 2006 and 2007, creating the OpenJDK project, and Oracle became Java’s steward when it bought Sun in 2010. Oracle then sued Google over Android’s use of Java APIs, a case that ended in 2021 when the U.S. Supreme Court ruled Google’s copying was fair use. Oracle also handed Java EE to the Eclipse Foundation, where it became Jakarta EE, moved to a six-month release schedule in 2018 and began charging commercial users for updates to older Oracle JDK builds in 2019.

1. 1995

   Sun Microsystems publicly announces the Java language and platform in May.

2. 1996

   Sun releases JDK 1.0, the first official Java Development Kit, in January.

3. 2006

   Sun begins releasing Java as open source under the GPL, leading to the OpenJDK project.

4. 2010

   Oracle becomes Java’s steward after completing its acquisition of Sun Microsystems.

5. 2014

   Java 8 adds lambda expressions and the Streams API, one of the language’s largest updates.

6. 2018

   Java 10 launches a six-month feature release cadence.

7. 2021

   The U.S. Supreme Court rules that Google’s use of Java APIs in Android was fair use.

8. 2026

   Java 27 reaches general availability on September 15.

Java pricing

Java alternatives

Profiled on SoftwareLore:

Also considerC#, Python, Go and Scala

Java: frequently asked questions

Sources

1. What is Java technology and why do I need it?, java.com java.com
2. JDK 27, OpenJDK openjdk.org
3. Oracle Java SE Universal Subscription oracle.com
4. Java (programming language), Wikipedia en.wikipedia.org

Last reviewed September 17, 2026. Spotted an error? Send a correction.