есть отличия?— Не, Киркоров мне не нравится. Слащавый он какой-то, подкрашенный весь, подпудренный как баба… Одно слово — румын.
— Так он болгарин.
— Да? Какая разница? ©

Lazarus and MSSQL/Sybase

You can connect to Microsoft SQL Server databases using

SQL Server data access Lazarus components.They are working on Windows and Mac OS X. Free to download.
The built-in SQLdb connectors TMSSQLConnection and TSybaseConnection (since Lazarus 1.0.8/FPC 2.6.2): see mssqlconn.
Zeos component TZConnection (latest CVS, see links to Zeos elsewhere on this page)
On Windows you can choose between native library ntwdblib.dll (protocol mssql) or FreeTDS libraries (protocol FreeTDS_MsSQL-nnnn) where nnnn is one of four variants depending on the server version. For Delphi (not Lazarus) there is also another Zeos protocol ado for MSSQL 2005 or later. Using protocols mssql or ado generates code not platform independient.
On Linux the only way is with FreeTDS protocols and libraries (you should use libsybdb.so).
ODBC (MSSQL and Sybase ASE) with SQLdb TODBCConnection (consider using TMSSQLConnection and TSybaseConnection instead)
See also [1]
On Windows it uses native ODBC Microsoft libraries (like sqlsrv32.dll for MSSQL 2000)
On Linux it uses unixODBC + FreeTDS (packages unixodbc or iodbc, and tdsodbc). Since 2012 there is also a Microsoft SQL Server ODBC Driver 1.0 for Linux which is a binary product (no open source) and provides native connectivity, but was released only for 64 bits and only for RedHat.