Java is a popular programming language used for developing applications and websites. It is an object-oriented language that is platform-independent, meaning it can run on any operating system. Java is used for developing web applications, mobile applications, desktop applications, and embedded systems. Major vendors for Java include Oracle, IBM, and Microsoft. Oracle provides the Java Development Kit (JDK) and Java Runtime Environment (JRE) for developing and running Java applications. IBM provides the IBM Java SDK and IBM WebSphere Application Server for developing and deploying Java applications. Microsoft provides the Microsoft Java Virtual Machine (MSJVM) for running Java applications.