help: installing modx revo using linux + mssql as database

can i install modx revo on linux using mssql server 2005 as a backend

No. MODX Revolution supports MS SQL Server 2005+ as a database backend ONLY on the Windows platform via the more recent SQLSRV native PDO driver. This driver ONLY works on Windows platforms. MS is working on a separate driver for Linux platforms, but we are not actively working on incorporating support for this at this time.