The question is simple, I need to know if what I'm doing has any sense.
I need to know is there exists some 100% free OBDC driver to connect to Progress 9.1D database.
Thinks of a multiuser installation where many 3 or 4 machines will need to connect to progress via ODBC.
Does this ODBC driver uses a licence?
As far as I remember, the ODBC driver is shipped with the development tools, servers and client networking.
All connections use a license. If you have 2 or more connections from a single PC (note PC not Citrix Server) then only the first connection counts aas a license, the rest count as a connection.
If you were on a vaguely modern version of Progress, the answer would be yes. All 10.x releases have a free download SQL client from the ESD site. In prior releases, the client was available as part of Client Networking and SQL Networking, both licensed products. Not expensive, but not free. The server side is a standard part of the server product and has been since there was SQL.