As of recent years, ACD/Labs has phased standalone viewers in favor of the (browser-based), which requires an account.
Bruker offers a free version of TopSpin for academic users to process NMR data. acd spectrus processor free download
ACD/Labs offers a fully functional, time-limited trial of the Spectrus Processor. This is not a watered-down "viewer"; it includes almost all processing and reporting tools. As of recent years, ACD/Labs has phased standalone