using the mssql functions on a linux server

This may be a dumb question but how do I enable the mssql extension on a Linux server...if possible? I have a site which needs to connect to a mssql db. On my windows server, I just enable the mssql.dll extension...how do I do it on the Linux server? Thanks, Eddie WARNING: The information contained in this message and any attachments is intended only for the use of the individual or entity to which it is addressed. This message may contain information that is privileged, confidential and exempt from disclosure under applicable law. It may also contain trade secrets and other proprietary information for which you and your employer may be held liable for disclosing. You are hereby notified that any unauthorized dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify HIPAA@echoman.com by E-Mail and then destroy this communication in a manner appropriate for privileged information.