This is largely a momentum release but it does introduce a few new user-facing features and some important changes under the hood which will be of interest to developers and distributors.

First, the CLI has a couple of new commands:

• rkt trust can be used to easily add keys to the public keystore for ACI signatures (introduced in the previous release). This supports retrieving public keys directly from a URL or using discovery to locate public keys - a simple example of the latter is rkt trust --prefix coreos.com/etcd. See the commit for other examples.
• rkt list is an extremely simple tool to list the containers on the system

As mentioned, v0.3.0 includes two significant changes to the Rocket build process:

• Instead of embedding the (default) stage1 using go-bindata, Rocket now consumes a stage1 in the form of an actual ACI, containing a rootfs and stage1 init/exec binaries. By default, Rocket will look for a stage1.aci in the same directory as the location of the binary itself, but the stage1 can be explicitly specified with the new -stage1-image flag (which deprecates -stage1-init and -stage1-rootfs). This makes it much more straightforward to use alternative stage1 images with rkt and facilitates packing it for different distributions like Fedora.
• Rocket now vendors a copy of the appc/spec instead of depending on HEAD. This means that Rocket can be built in a self-contained and reproducible way and that master will no longer break in response to changes to the spec. It also makes explicit the specific version of the spec against which a particular release of Rocket is compiled.

As a consequence of these two changes, it is now possible to use the standard Go workflow to build the Rocket CLI (e.g. go get github.com/coreos/rocket/rkt will build rkt). Note however that this does not implicitly build a stage1, so that will still need to be done using the included ./build script, or some other way for those desiring to use a different stage1.

This release introduces countless fixes since v0.1.1, along with several important new subcommands (rkt status, rkt enter, rkt gc), and signature validation when retrieving images.

The most significant change in this release is that the spec has been split into its own repository (https://github.com/appc/spec), and significantly updated since the last release - so many of the changes were to update to match the latest spec.

Numerous improvements and fixes over v0.1.0:

• Rocket builds on non-Linux (in a limited capacity)
• Fix bug handling uncompressed images
• More efficient image handling in CAS
• mkrootfs now caches and GPG checks images
• stage1 is now properly decoupled from host runtime
• stage1 supports socket activation
• stage1 no longer warns about timezones
• cas now logs download progress to stdout
• rkt run now acquires an exclusive lock on the container directory and records the PID of the process

• tons of documentation improvements added
• actool introduced along with documentation
• image discovery introduced to rkt run and rkt fetch

Initial release