nexuiz-glx: 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/nexuiz-glx - from package: darkplaces

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

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