Unix-Linux Dynamic Extensions

this is PHP.INI it shows all the windows extensions available for automatic loading,. anyone know why the UNIX extensions are NOT listed? Ken ;;;;;;;;;;;;;;;;;;;;;; ; Dynamic Extensions ; ;;;;;;;;;;;;;;;;;;;;;; ; if you wish to have an extension loaded automaticly, use the ; following syntax: extension=modulename.extension ; for example, on windows, ; extension=msql.dll ; or under UNIX, ; extension=msql.so ; Note that it should be the name of the module only, no directory information ; needs to go here. Specify the location of the extension with the extension_dir directive above. ;Windows Extensions ;Note that MySQL and ODBC support is now built in, so no dll is needed for it. ; ;extension=php_bz2.dll ;extension=php_ctype.dll ;extension=php_cpdf.dll ;extension=php_curl.dll ;extension=php_cybercash.dll ;extension=php_db.dll ;extension=php_dba.dll ;extension=php_dbase.dll ;extension=php_domxml.dll ;extension=php_dotnet.dll ;extension=php_exif.dll ;extension=php_fdf.dll ;extension=php_filepro.dll ;extension=php_gd.dll ;extension=php_gettext.dll ;extension=php_ifx.dll ;extension=php_iisfunc.dll ;extension=php_imap.dll ;extension=php_interbase.dll ;extension=php_java.dll ;extension=php_ldap.dll ;extension=php_mhash.dll ;extension=php_mssql.dll ;extension=php_oci8.dll ;extension=php_openssl.dll ;extension=php_oracle.dll ;extension=php_pdf.dll ;extension=php_pgsql.dll ;extension=php_printer.dll ;extension=php_sablot.dll ;extension=php_snmp.dll ;extension=php_sybase_ct.dll ;extension=php_yaz.dll ;extension=php_zlib.dll ;;;;;;;;;;;;;;;;;;; goes on to something else here..