icewm-experimental: 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 Debian possible default full paths are:

/usr/bin/icewm-experimental - from package: icewm-experimental

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

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