It just works!
Lately Active4D v6.1 was released by Aparajita Fishman, supporting native JSON capabilities:
The existing a4d.json library has been converted to a new suite of native JSON commands. Converting data to JSON is now 24x to 40x faster than the a4d.json methods, and JSON parsing is now 50x faster! The a4d.json library has now been reimplemented as a thin wrapper around the native commands, so it gains all of their speed.
In addition to the great new JSON features, there are new security features as well. Support has been added for the Secure and HttpOnly attributes of cookies, and session cookies are now marked HttpOnly to help protect against XSS attacks.
The update is free for existing license holders, but you will need to request a new key file at email@example.com. Otherwise, there is an update for just $270.
There are no reported issues using 4D v14 and Active4D together. Good to know!