Rocket 接连发布两个版本，0.4.0 和 0.4.1，其中 0.4.0 与 0.3.2 版本比较改进内容包括：
Updated to v0.4.0 of the appc spec
Introduced a database for indexing local images in the CAS (based on github.com/cznic/ql)
Refactored container lifecycle to support a new "prepared" state, to pre-allocate a container UUID without immediately running the application
Added support for passing arguments to apps through the rkt run CLI
Implemented ACI rendering for dependencies
Renamed rkt metadatasvc -> rkt metadata-service
Added documentation around networking, container lifecycle, and rkt commands
而 0.4.1 则修复了 0.4.0 的如下 bug：
Fix marshalling error when running containers with resource isolators
Fixup help text on run/prepare about volumes
Fixup permissions in rkt trust created files
Introduce the rkt install subcommand
Rocket 是 CoreOS 推出的类似 Docker 的应用容器。该项目目前还只是一个原型阶段。
软件详情：https://github.com/coreos/rocket
来自:开源中国社区
