ubuntu13.04发行计划：

Ubuntu 13.04 Alpha 1 – 12月1日
Ubuntu 13.04 Alpha 2 – 2月7日
Ubuntu 13.04 Beta - 3月7日
Ubuntu 13.04 Final - 4月25日

更新源：

deb http://archive.ubuntu.com/ubuntu/ raring main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ raring-security main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ raring-updates main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ raring-proposed main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ raring-backports main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ raring main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ raring-security main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ raring-updates main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ raring-proposed main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ raring-backports main restricted universe multiverse