The trial version is fully functional. The only differences between the trial version and the full version are listed as below:

1. Trial version: You will get a message "Thank you very much for evaluating Dynamic Web TWAIN" when you open the web page or run the application.



Full version: the message will never appear with the full version of Dynamic Web TWAIN.

2. Trial version: The license will be expired. You will get your 30 day trial after you download Dynamic Web TWAIN.



Full version: The full version license is permanent.

3.  Trial version and full version have different class ids:

Trial version classid: <object classid="clsid:FFC6F181-A5CF-4ec4-A441-093D7134FBF2" id="DynamicWebTwain1" ...

Full version classid: <object classid="clsid:E7DA7F8D-27AB-4EE9-8FC0-3FEC9ECFE758" id="DynamicWebTwain1" ...

References:

To download the trial version of Dynamic Web TWAIN (DWT), please go to:
DWT Download

To purchase Dynamic Web TWAIN, please refer to:
Purchase