ocamlmktop: 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 CentOS possible default full paths are:

/usr/bin/ocamlmktop - from package: ocaml

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/ocamlmktop - from package: ocaml-nox

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

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