You need Progress SQL92 Client Access, Mac is unsupported, RedHat, SuSe and several flavours of Unix are.
See Progress Version 9 product availability matrix, look for ODBC and JDBC.
As far as I know there are only two companies in the world that produce ODBC/JDBB connectivity drivers for Progress DB: OpenLink and DataDirect (now acquired by Progress).
Another way is to connect using Progress AppServer, then you'd be able to run Progress 4GL (or ABL - Advanced Business Language) queries/logic on AppServer and output resulting datasets to Java.
The third way is to migrate the data (if this is an option).
Other options include exposing DB via WebSpeed (web application server) or using sockets, files, getting OpenEdge and exposing the data through 4GL web services etc. This will really depend on your data access needs. However all of these methods are non-trivial and require Progress platform and 4GL expertise.