Note that, for a new plugin, you should build a bootstrapped extension rather than creating a XUL overlay extension, since the former will be much easier to port to a future non-Mozilla architecture. Similarly, when creating UI in a new window, or non-trivial UI in an existing window, use HTML instead of XUL.
If you have other technical questions, please post to zotero-dev. We try to keep technical discussions there.
Upgrade Storage
Note that, for a new plugin, you should build a bootstrapped extension rather than creating a XUL overlay extension, since the former will be much easier to port to a future non-Mozilla architecture. Similarly, when creating UI in a new window, or non-trivial UI in an existing window, use HTML instead of XUL.
If you have other technical questions, please post to zotero-dev. We try to keep technical discussions there.