Doug, KR2Q, did some quick analysis of the logging software used by entrants in the 2018 CQ WW SSB Contest. This information is taken from the CREATED-BY field in the Cabrillo log. The table shows the top 40 by count.

Logging programCount of logs% of logs
N1MM386647.24%
N3FJP’S5847.14%
LZ2FQ-ADIF2CABRILLO5316.49%
WIN-TEST5206.35%
TR4W3253.97%
QARTEST3033.70%
UCXLOG2753.36%
JA1AQY-CTESTWIN2483.03%
WRITELOG1541.88%
5MCONTEST1271.55%
WA7BNM_WEB2CAB1241.52%
LM1131.38%
AATEST1101.34%
DXLOG.NET1031.26%
WINURECON780.95%
SD710.87%
MIXW590.72%
DQR_LOG570.70%
RUMLOGNG510.62%
UR5EQF_LOG500.61%
SP7DQR-ADIF2CABR360.44%
ZLISTW(ZLOG)280.34%
GENLOG270.33%
RUSSIAN_CONTEST_LOG260.32%
CT220.27%
RADIOGES200.24%
DXKEEPER190.23%
CONTESTLOGCHECKER180.22%
SUPERLOGGER150.18%
SKOOKUMLOGGER150.18%
VK3AVV_CONTEST_LOG140.17%
HAM_OFFICE140.17%
TRLOG130.16%
XLOG110.13%
FAST_LOG_ENTRY100.12%
CABCONVERTER-NE1RD100.12%
LOGHX90.11%
TLF70.09%
Z2CABRIL.EXE70.09%

LZ2FQ-ADIF2CABRILLO is the adif conversion page on the cqww.com web site.