Hi,

Version 4-7 can be used with DataFlex 18.0. Starting with v6 the print engine can use report definitions older than the version current when the print engine (the OCX) was made. Older versions cannot use newer report definitions.

Note that v7 dates 2019 (so 3 years now) and the earlier versions (officially not longer supported) are much older.

For licensing; as developer you need to purchase the developer edition and when it is for the web you need a web deployment license per webserver. Windows deployment is royalty free.