Any new VMDs created with version 4.0 and later are automatically saved in the new file format, and
VMDs open much faster in version 4.0 and later than VMD files opened in version 3.3. This was improved by changing the internal file format that Chameleon is saved in to an earlier format, resulting in faster serialization.
If you are using Chameleon 4.0 and later in a test environment and load the VMD into any 3.3 version, please review the user implications under Version 3.3 Users.
To avoid any unexpected problems, iNTERFACEWARE recommends that you use Chameleon 4.0 and later in both test and production environments.