Here are the websites for most of the common logging programs. Here you will find the most recent versions, FAQs, and often support forums.

Logger 32 by K4CY
http://www.logger32.net/

DX4WIN
http://www.dx4win.com/

Prolog 2K - Datamatrix
http://www.prolog2k.com/

ACLog - N3FJP
http://www.n3fjp.com/

Logic 8 from PDA
http://www.hosenose.com/logic/

VQLog by EA6VQ
http://www.vhfdx.net/vqlog.html

MacLoggerDX by Dog Park Software
http://www.dogparksoftware.com/MacLoggerDX.html

Win-EQF
http://www.eqf-software.com/

nGenLog
http://www.ngenlog.com/

DXLab Suite
http://www.dxlabsuite.com/

N1MM Logger
http://pages.cthome.net/n1mm/

MixW Logbook
http://www.mixw.co.uk/product/productmixw.htm