Shareware DefinedShareware = Trialware is try-before-buy computer software.
Shareware includes some of the best software values available, and many commercial programs started as shareware or freeware. New products often cannot support advertising costs, so versions with time or feature restrictions can be distributed freely to invite purchase of unlock keys.
Reasons for high value include these:
1. After developing programs for private use, authors can decide that other people might be interested.
2. Programs developed by government funded facilities can be released to the public for free, perhaps with later upgrades by other programmers.
3. Some good programmers do other things for main income.
An example is a popular photo-editing product which was initially developed by an airline pilot as a hobby. Many utilities, games, and so forth are developed as hobby projects.
A google.com search finds millions of hits for shareware.
For example, two of the largest down-load sites are TuCows.com and download.com (now a division of CNET.com).
Two major problems with many internet shareware directories are:
1. A large fraction of the download links can be dead or in need of updating.
2. Site search engines can be idiots, prone to false hits or no hits for one's personal interests.
Some of the reasons that shareware links can die are these:
1. Authors lose interest and/or health.
2. Sales don't cover web-site costs.
3. Commercial products costing many times as much for very similar features have swept the public interest through heavy promotion.
4. Sites hosting the downloads go out of business.