MUSCLE 5.63 发布，该版本改进如下：

This release adds optional support for basing the ReflectServer event loop around poll() instead of select. It also makes the socket-pair in the Thread class optional, adds a couple of new methods to the Queue class, and makes the multicast API enabled by default.

MUSCLE 用来在网络上传输消息对象，所有消息存储在服务端并为客户端进行传递。