Protobuf 2.6.0 发布，此版本现已提供下载，更新内容如下：
常规更新添加 oneofs(unions) 功能。Fields in the same oneof will share
memory and at most one field can be set at the same time. Use the
oneof keyword to define a oneof like: message SampleMessage {
oneof test_oneof {
string name = 4;
YourMessage sub_message = 9;
}
}Files, services, enums, messages, methods and enum values can be marked
as deprecated now. 解析 Java 和 C++ 文本格式 protos 时， 添加对 list values 的支持，包括 lists of messages For example: foo: [1, 2, 3]
C++Enhanced customization on TestFormat printing. Added SwapFields() in reflection API to swap a subset of fields.
Added SetAllocatedMessage() in reflection API. Repeated primitive extensions are now packable. The
[packed=true] option only affects serializers. Therefore, it is
possible to switch a repeated extension field to packed format
without breaking backwards-compatibility. Various speed optimizations.
JavawriteTo() method in ByteString can now write a substring to an
output stream. Added endWith() method for ByteString. ByteString and ByteBuffer are now supported in CodedInputStream
and CodedOutputStream. java_generate_equals_and_hash can now be used with the LITE_RUNTIME.
Python
Protocol Buffers (ProtocolBuffer/ protobuf )是Google公司开发的一种数据描述语言，类似于XML能够将结构化数据序列化，可用于数据存储、通信协议等方面。现阶段支持C++、JAVA、Python等三种编程语言。 为什么不只用XML？同XML相比，Protocol buffers在序列化结构化数据方面有许多优点（google官方提出）： 更简单 数据描述文件只需原来的1/10至1/3 解析速度是原来的20倍至100倍 减少了二义性 生成了更容易在编程中使用的数据访问类
google大概是今天(08年7月8号)将其作为开源项目对外公布，说是后续还要开源的项目有不少都会用到Protocol Buffers。 | 
