The difference between openJdk and JDK in linux (transfer)

Anyone who has used LINUX should know that in most LINUX distributions, if the JDK is built-in or installed through software sources, it is installed with openjdk. Then the relationship and difference between openjdk and sun jdk are as follows:
The historical reason is that openjdk Is the open source version of jdk, released in the form of GPL agreement. At the time of JDK7, openjdk has become the main development of jdk7, sun jdk7 is released on the basis of openjdk7, most of its original code is the same, only a small part of the original code has been replaced. Released using JRL (JavaResearch License, Java Research License).
As for openjdk6, it has its complicated side. First, openjdk6 is a branch of jdk7, and try to remove the new features of Java SE7 to make it conform to the Java6 standard as much as possible.
The difference between JDK and OpenJDK can be summarized into the following points:
Differences in licensing agreements:
openjdk is released using the GPL V2 protocol, while JDK is released using JRL. Although both protocols are open source, the difference in use is that GPL V2 allows commercial use, while JRL only allows personal research and use.
OpenJDK does not include Deployment (deployment) functions:
the deployment functions include: Browser Plugin, Java Web Start, and Java Control Panel, which are not found in Openjdk.
The OpenJDK source code is incomplete:
It is easy to think that in the Openjdk using the GPL protocol, part of the source code of sun jdk cannot be used by openjdk due to property rights. The most important part is the code of the optional component SNMP in JMX. Therefore, these can not open source code to make it into a plug for OpenJDK compile time, you can also choose not to use plug. And Icedtea developed the source code (OpenJDK6) of the same function for these incomplete parts, making OpenJDK more complete.
Part of the source code is replaced with open source code:
Due to property rights issues, many source codes that are not owned by SUN are replaced with some open source codes with the same functions, such as font rasterization engines, which are replaced by Free Type.
openjdk only contains the most compact JDK:
OpenJDK does not contain other software packages, such as Rhino Java DB JAXP..., and the separable packages are also separated as much as possible, but most of these are free software, you can download it yourself join in.
Can't use Java trademark:
This is easy to understand, on the machine where openjdk is installed, typing "java -version" shows openjdk, but if it is openjdk with the Icedtea patch, it shows java. (Unverified)