US : GCALDaemon is an OS-independent Java program that offers two-way synchronization
between Google Calendar and various iCalendar compatible calendar applications.
GCALDaemon is primarily designed as a calendar synchronizer but it can also be used as a
Gmail notifier, Address Book importer, Gmail terminal and RSS feed converter.
FR : SYNC SYNCHRO Google Calendar et les application supportant ICAL
GCALDaemon permets aussi l’import des Addresse de Gmail, peu faire office de convertisseur de RSS, et pour finir fait un bon terminal pour GMAIL
FONCTIONS / FEATURES / MUCHO VERY PRATICOS (ndlr : ne pas chercher a traduire c’est un nouvau concept 
Open source and completely free of charge
OS-independent standalone application (Java 1.5)
Bidirectional sync between iCalendar and Google Calendar
View and edit your Google Calendar offline
Supports ‘Google Apps for Your Domain’
Supports multiple file listeners with multiple Google Accounts
Makes Gmail contacts accessible via LDAP
Customizable Gmail notification
Converts RSS/ATOM feed to iCalendar format
Reusable mail transfer agent
Remote control your computer via Gmail
Multi-user abilities (up to 30-40 HTTP and LDAP clients)
Run in service mode on Windows NT/2000/XP
Run in embedded mode in a Servlet Container
Low memory usage (10-20 MBytes)
Automatic and fast (3-5 sec/sync)
Customizable logging system (Log4J / CommonsLogging)
Ability to do TCP/IP hostname/address filtering
Ah Mince vous lisez cette article pour l’adresse du Produit :
here is a good gmail notifier for Google Apps http://gmailnotifier.net/