If all those version numbers in the title don’t confuse you I don’t know what will.

Notes 8.5.3 ships with Sametime 8.5.1, but can be upgraded to Sametime 8.5.2.  Depending on your entitlement there are two packages you can download to upgrade the embedded Sametime client, depending on your entitlement.

Under the Notes/Domino product family you will find part number CZZ92ML provided as part of the Sametime Entry entitlement

Under Sametime you will find Part Number CZYF7ML

either way to get the installer for the Notes client you are looking at a 2GB download.  The Installer is the same in either download.  Once you extract the zip file you are looking for SametimeEntryClient\sametimeclient.for.notes directory if you used CZZ92ML or SametimeStandardClient\sametimeclient.for.notes directory if you used CZYF7ML where you will find installs for  Windows, Mac and Linux.

For Windows it is an installer, for Linux a couple of package flavors, and for Mac there are install instructions available in a readme file.

For more information on upgrading and instructions how to check your Sametime version in Notes see this entry on upgrading to Sametime 8.5.1 in Notes 8.5.2.

I have already heard a number of people as “why didn’t they just ship it with 8.5.2” fair question, the answer I am sure has to do with timing of the Sametime 8.5.2 release and time to package in Notes 8.5.3 for shipping.  The reality is I don’t care what version of Sametime ships embedded with Notes, what I care is that I can get the version I want without changing the Notes client version so this is fine with me.

From the Sametime Wiki Upgrading the IBM Lotus Sametime client embedded in IBM Lotus Notes to Lotus Sametime 8.5.1 or 8.5.2