netsurf-gtk: 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/netsurf-gtk - from package: netsurf-gtk

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

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