These flash clocks will run on any computer that has a flash player or flash codec installed. You can distribute these flash clocks absolutely free without charging any cost of any sort and without modification to the flash clocks. All the clock you find in website can download in a single. I recommend you download my Free Flash Clocks called MatsClocks which are free beautifully animated analog flash clocks. You may buy a clock only if absolutely essential and you have the money.