xchat: 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/xchat - from package: xchat

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

On Debian possible default full paths are:

/usr/bin/xchat - from package: xchat

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

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