How to make AGSatellite work in Linux
 

I used AGSatellite in Windows for months with satisfaction.
Now that I migrated to Linux, I tried to make its Linux version work, but I did not succeed.
I downloaded its both versions (the glibc and the static versions).
I prepared the account.txt and shares.txt files, then I tried to run both binaries from a terminal window of KDE but I got the following message:
bash: AGSatellite: command not found
Also tried to run the binaries from the KDE file manager: I see some HDD activity, but nothing else happens.
Tried to switch to an other terminal CTRL+ALT+F2 and run the binary there, but I got the same error message as mentioned above.
In general: why do I get a 'command not found' message, when running a binary in a terminal window?

You get the error message: bash: PROG: command not found
when the PROG doesn't exist in you PATH(where executables are located), try issuing the command dgf78sg for example you will get the same error, because that command doesnt exist.

either add the path where the executable is to your path, for example if it's in /home/user/bin/PROG you should do something like: PATH=$PATH:/home/user/bin. Or you can simply change to the directory where you have the binary file (using cd) and execute it maually: cd /home/user/bin (i.e.) and then: ./PROG

if you still get the same error or another related to prmissions, check the permission using: ls -l

you should have x (execute) permission.
change with chmod 755 PROG if you don't.

Audiogalaxy
 

When I tried to run Audiogalaxy, I was always in the directory where it is located, and I was root user.
That is why I do not understand this.

Well the current directory is usually not included in the path. So even if you are running something in the current directory you still need to include the path.
So like h1kz0r said run ./AGSattelite and not just AGSattelite.