CLI client driver is *still* well-known as "DB2 CLI" in the industry. So I just want break the ice here a bit and explain why it was fine saying "DB2" CLI earlier and now we better call it as "IBM Data Server CLI" or just CLI to keep it simpler.
Before IBM acquired Informix Inc. in July-2001, IBM's CLI client driver used to support these IBM Database product lines: DB2 on LUW (UDB), DB2 on zSeries (mainframes), DB2 on iSeries. But post Informix acquisition, IBM put extensive efforts in getting Informix's IDS (Informix Dynamic Server) complied to a DRDA protocol (a common protocol used across all IBM database servers listed before). So now starting with 9.7 FP1, our CLI driver (which also adheres to DRDA protocol while talking with each IBM database servers) officially supports IDS version 11.10.
As IDS is not DB2!, it is now unfair to call our CLI package "DB2" CLI. Hence now we refer CLI as either IBM Data Server CLI or just CLI and you would have noticed this getting reflected pretty much where it's feasible to do so. Unfortunately, this change does not get reflected in our product files (for example, we cannot rename db2cli.ini, db2dsdriver.cfg that easily to ensure proper backward compatibility etc.), but for all documentation purpose, our attempt was to get new terminology reflected.
With IDS support with CLI, you can leverage having common CLI application talking to DB2 product-lines and IDS (you can very well have same application dealing with both DB2 and IDS using different connection handles!).
