zf.php: command not found

Have You tried accessing the binary with the full path?

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

[root@server ~]# echo $PATH

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/share/zendframework/bin/zf.php - from package: zendframework-bin

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