supybot: 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/supybot - from package: supybot-gribble
/usr/bin/supybot - from package: supybot

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

On Debian possible default full paths are:

/usr/bin/supybot - from package: supybot

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

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