Antenna Modeling:

EZNEC 

CocoaNEC (for MAC)  

Logging:

N3FJP Logging Software

Worked Grids for Windows - mapping application for grid square display from ADIF files

Logger32 General Logging

Propagation Prediction:

W6EL Prediction Software

Digital Operating:

WSJTX/FT8

JS8Call

Winlink - e-mail via ham radio gateways

Ham Radio Deluxe - sophisticated combination for logging and multiple modes of digital operation

WSJT9 - digital mode for meteor shower operation

Radio Programming:

RT Systems

Radio Software

CHIRP

QSLs:

QSL Maker

HRD Label (works with Ham Radio Deluxe)

DX Spotting:

DXWatch

CC Cluster - a very versatile package that includes the ability to generate e-mail alerts per individual filters