Importing from Netscape Calendar into iCal
This is very easy and quick.
Just choose Export Data in the File menu in Netscape Calendar, select "vCalendar file" as the format in the ensuing Export dialog box, click "OK", select the period and types of events/tasks to save in the next "Export" dialog box, click "OK" and save it to your hard drive.
The data are saved as a ".vcs" file.
Then choose "Import" under iCal's File menu, choose "vCal format" in the ensuing dialog box, navigate to the saved .vcs file and click "Import."