This might be hard to explain. So right now you and your freind might be trading software. So each time one of you have a new version, your freind needs to redownload the whole file again. Then you need to delete your old version right after. That takes alot of time and some AP. What I was thinking, if your already have that type of Program, you dont need to download the whole next version, insted you upgrade your current one.
E.G.
You have a v1 log deleter and your friend has a v2.
So you go to the public FTP, and beside the download for the v2 log deleter theres an opption for upgrade, you click on it. Then before it starts it will ask you which one of the log deleters you have you would like to upgrade. You choose your v1. So insted of downloading the full 100mb, you only need to downlaod the differents. So you would only need to download the 50mb differents.
Now insted of have 2 different versions of the same file, you now have only have the original but its now a v2. The ID# wouldnt change.
This idea has to be worth a gold medal.
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Edit- Horrible grammer.