Compose in a tab

This extension is a Mozilla Messaging experiment whose broad goal is to update the whole composition process. This includes:

• rewriting (most parts of) nsMsgCompose.cpp in JS,
• integrating an external composition UI (e.g. CKEditor),
• add bonus features, like compose in a tab.

This is a proof-of-concept, so we do not expect you to use this for real. See the [companion blog post] labs for more details. Feedback and updates are welcome on [Google Groups] groups.