Which version of SharePoint?

Update 29.04.2010: I added the latest CUs for February and April 2001. The download for the April CU doesn’t seem to be available yet, so I cannot provide any version numbers.

There are currently a lot of updates available for SharePoint (Services as well as Portal Server), like SP1, Infrastructure Rollup, SP2 and various cumulative updates. That makes it hard to keep up to date with the latest patch-level. This little table should give some overview:

Update Name owssvr.dll Microsoft.SharePoint.portal.dll
RTM 12.0.4518.1016 12.0.4518.1016
October public update (2007) 12.0.6039.5000 12.0.6036.5000
Service Pack 1 12.0.6219.1000 12.0.6219.1000
Post-Service Pack 1 rollup 12.0.6300.5000 12.0.6300.5000
Infrastructure Update (IU) 12.0.6320.5000 12.0.6320.5000
August Cumulative Update (2008) 12.0.6327.5000 12.0.6327.5000
October Cumulative Update (2008) 12.0.6331.5000 12.0.6331.5000
December Cumulative Update (2008) 12.0.6335.5000 12.0.6335.5000
February Cumulative Update (2009) 12.0.6341.5000 12.0.6341.5002
Service Pack 2 12.0.6421.1000 12.0.6420.1000
April Cumulative Update (2009) 12.0.6504.5000 12.0.6504.5000
June Cumulative Update (2009) 12.0.6510.5001 12.0.6507.5000
August Cumulative Update (2009) 12.0.6514.5000 12.0.6514.5002
October Cumulative Update (2009) 12.0.6520.5000 12.0.6520.5000
February Cumulative Update (2010) (WSS, MOSS) 12.0.6529.5000 12.0.6529.5000
April Cumulative Update (2010) (WSS, MOSS)    

To verify the version of SharePoint you’re running go to %CommonFiles%\Microsoft Shared\Web Server Extensions\12\ISAPI and look at the file-versions of owssvrdll and/or Microsoft.SharePoint.portal.dll.

To get detailed information about hwo to deploy updates for SharePoint, check the TechNet sites on Deploy software updates for Windows SharePoint Services 3.0 and Deploy software updates for Office SharePoint Server 2007.