As part of its acquisition of Sun Microsystems, Oracle also acquired the Java technology. Oracle has the enterprise sector in its grip now (Java and Oracle database). However, we cannot forget how erratic it has been in handling delicate issues like the OpenSolaris project or the ongoing infringement case against Android. It has repeatedly failed to earn the trust of the Open Source community, something that Sun Microsystems had in abundant.
Java is a wonderful technology. This video from 2006 will tell you why.
The Java development kit comes in two flavors. While Oracle JDK (earlier Sun JDK) is under the Binary Code License (earlier Sun License), OpenJDK is under GPL with a linking exception. From JDK version 7, Oracle has planned to support OpenJDK and withdraw the Operating System Distributor License for Java. This has resulted in a withdrawal of OracleJDK from the repositories of Linux distributions. Putting further restrictions, you cannot even download Oracle Java for any Linux distributions anymore.
OpenJDK has always suffered because of the unfair nature of the competition and it is said to have some serious bugs. These pitfalls never allowed it a rise to fame but now, things are looking better for OpenJDK. Oracle itself has taken interests in OpenJDK development. Perhaps for uniformity, it has declared OpenJDK as the official Java SE reference from JDK 7 onwards.
This is the second game changing event in the world of Java since May 2007, when it went completely open-source and the Java code was released under GPL. With IBM, Oracle, Apple, SAP, RedHat and other big names working on the OpenJDK project, we will surely see the best of Java in future.
Do you want to know how OpenJDK fares against Oracle JDK? Read this Stack Overflow question.