uzbl-browser: 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/uzbl-browser - from package: uzbl

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

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