Download free, legal, full versions of softwares

Every day giveawayoftheday.com offer for free licensed software for download. The software will be available for download for 24 hours or more. For the first time Free (also means) its not a trial, not a limited version, but a registered and legal version of the software (which limit the software usage to non-commercial only, and may also limit software updates and technical support.)

There are many useful softwares which I could use in my everday life. Its worth a visit. Wonder what makes developers give them free of charge to them? how they do it?