The PHP Encoding Converter can be used to easily batch convert your language pack to the UTF-8 encoding (or to another encoding type). Over 50 encoding types are supported (Windows, Dos, Unix, Mac). The script batch converts directories from one encoding type to another and can be run from a webserver (or local server with for example Xampp installed).

Supported encoding types:

WINDOWS
windows-1250 - Central Europe
windows-1251 - Cyrillic
windows-1252 - Latin I
windows-1253 - Greek
windows-1254 - Turkish
windows-1255 - Hebrew
windows-1256 - Arabic
windows-1257 - Baltic
windows-1258 - Viet Nam
cp874 - Thai - this file is also for DOS

DOS
cp437 - Latin US
cp737 - Greek
cp775 - BaltRim
cp850 - Latin1
cp852 - Latin2
cp855 - Cyrylic
cp857 - Turkish
cp860 - Portuguese
cp861 - Iceland
cp862 - Hebrew
cp863 - Canada
cp864 - Arabic
cp865 - Nordic
cp866 - Cyrylic Russian (this is the one, used in IE "Cyrillic (DOS)" )
cp869 - Greek2

MAC (Apple)
x-mac-cyrillic
x-mac-greek
x-mac-icelandic
x-mac-ce
x-mac-roman

ISO (Unix/Linux)
iso-8859-1
iso-8859-2
iso-8859-3
iso-8859-4
iso-8859-5
iso-8859-6
iso-8859-7
iso-8859-8
iso-8859-9
iso-8859-10
iso-8859-11
iso-8859-12
iso-8859-13
iso-8859-14
iso-8859-15
iso-8859-16

MISCELLANEOUS
gsm0338 (ETSI GSM 03.38)
cp037
cp424
cp500
cp856
cp875
cp1006
cp1026
koi8-r (Cyrillic)
koi8-u (Cyrillic Ukrainian)
nextstep
us-ascii
us-ascii-quotes
utf-8