In the absence of SharePoint Services, FrontPage 2003 continues to require and use the FrontPage 2002 server extensions for those features that require server extensions. FrontPage 2003 also includes several new editing and publishing features that make creating and publish easier, even when using the FrontPage 2002 extensions.
So I believe the answer is that LunarPages supports FrontPage 2003 using the FrontPage 2002 server extensions. The advanced features that require SharePoint services would not be available.
This page may answer more questions.
http://www.microsoft.com/office/frontpage/prodinfo/faq.mspxThe chart on this page shows which features are available with which server configurations. LunarPages would be the column for "With Server Extensions for FrontPage 2002".
http://www.microsoft.com/office/frontpage/prodinfo/servers.mspx