This is a minor update to remain compatible with Sonoma (macOS 14).
This is a free update for existing users of Nisus Writer Express version 4.
If you are a user of Nisus Writer Express version 3 (or lower) this is a paid upgrade.
There are many new features in version 4.0
and it requires a new license key purchase.
Nisus Writer Express 4.4 is the latest version available.