version 4.11 mostly bug fixes since last version. version 4.10 added UDT_SNDDATA and UDT_RCVDATA options fixed a bug that causes unnecessary connection timeout improved epoll UDT event handling version 4.9 asynchronous close asynchronous connect some bug fixes, especially on EPOLL improved cache code removed unnecessary NAK (reduced loss retransmission) receiver side error can unblock a blocked sender version 4.8 fix a bug that may cause seg fault on concurrent close on the same socket add epoll support increase the listener's scalability to 100K concurrent connections fix a bug that may cause accept/select to return positively when an accepted socket is closed immediately after accept returns fix a bug that may cause connect to fail if the server closes listening socket immediately after accept returns fix recvfile fstream write status bug (e.g., when disk is full, recvfile should handle properly now) version 4.7a fix timeout bug introduced in 4.7 initialize CHandShake version 4.7 Fix several related bugs that can cause hang/memory leak/segmentation fault during cleanup()