The TreePad PLUS family
is the basic program in this group and contains the features you will need most of all.
offers all the features of TreePad PLUS together with password file encryption for text data. Encryption for images is not yet supported.
offers most of the features of TreePad Business Edition (eventually it will have all of the features), in addition to:
support for 384 or 12 Gigabyte databases of text+images, and opens up to 8 databases simultaneously
All of the features of the single-user version, in additional to multi-user access to databases.
See the online Feature chart for a full comparison of different versions.