joe: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/joe - from package: joe

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/joe - from package: joe-jupp
/usr/bin/joe - from package: joe

You may install the required package with command apt-get install {package}

Error in other languages:
joe: bevel nie gevind nie
joe: comandă negăsită
joe: comando não encontrado
joe: commande introuvable
joe: command not found
joe: käsku ei ole
joe: không tìm thấy lệnh
joe: komanda nerasta
joe: Kommando nicht gefunden.
joe: kommandot finns inte
joe: komut yok
joe: nie znaleziono polecenia
joe: níor aimsíodh an t-ordú
joe: no se encontró la orden
joe: no s'ha trobat l'ordre
joe: opdracht niet gevonden
joe: parancs nem található
joe: perintah tidak ditemukan
joe: príkaz nenájdený
joe: příkaz nenalezen
joe: команда не найдена
joe: командата не е открита
joe: 命令找不到
joe: コマンドが見つかりません