4D offers a wide range of features that enhance the functionality of databases. Some of these features, however, require an expansion license if you would like to implement them on your database. Finding the exact license you need can be a little confusing, so you can find quick explanation of each license below:

• Client Expansion: Increases the number of 4D remote clients


• 4D Write Pro: Adds the 4D Write Pro feature to your database (requires a client expansion for each client that used Write Pro)


• 4D View Pro: Adds the 4D View Pro feature to your database (requires a client expansion for each client that used View Pro)


• Web Application: Allows unlimited web client connections for the web server (a separate Web Application for 4D clients is also available)


• Web Services: Allows the 4D web server to host web services (a separate Web Services for 4D clients is also available)