Thanks Darshaka and Evgeni.
I didn't trust too much in md5 sums as I have seen in other daily build distro and unchanged/unmodified iso that the day it was build for the first time, lets say on 09 January, had x md5 then the automatic build system, rebuilt it again the next day, 10 January, and its md5 was different, who knows it could be the simple different number in the date or a glitch during the automatic build process, iso sizes were exactly the same, the iso was a final version so nothing was modified by the devs because they only add or change things between final versions not a day after a final version is released and their md5 were different.
That's why I thought the same thing happens in grml, iso is the same unless you see an increase or decrease in its size, md5 can be different as a matter or different date coded in the build so if you see the same size in 3 consecutive daily builds then you can expect no browser update, no openssl update and the like.
I don't know if the autobuild systems are controled by anything/anyone or if they simply keep rebuilding isos on a daily basis and autonomous way no matter if modifications were made or not, something like: It was programmed to do a rebuild every day at 11:00 or so
Thanks much for your replies.
