“The Mozilla Foundation has published an initial roadmap for
‘Lightning,’ the project to integrate its calendar application
Sunbird with its e-mail application Thunderbird. Sunbird has been
available as a separate extension for Firefox and Thunderbird for a
while, but there’s been little integration between calendar and
e-mail functionality.“The team working on Lightning–a code name, rather than an
official product name at present–hope that the integration of
scheduling and tasks with Thunderbird’s e-mail capabilities will
make the combined application more attractive to corporate users,
although they’re not specifically targeting Microsoft
Outlook…”