wmfrog: 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/bin/wmfrog - from package: wmfrog

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