This post contains copies of all contributed character transliterations from this thread as well as previous one. Origins of older deLocalize() versions summarized in this post can be found
here 
Turkish:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[çÇ]/g, 'c');
outStr = outStr.replace(/[ğĞ]/g, 'g');
outStr = outStr.replace(/[ıI]/g, 'i');
outStr = outStr.replace(/[öÖ]/g, 'o');
outStr = outStr.replace(/[şŞ]/g, 's');
outStr = outStr.replace(/[üÜ]/g, 'u');
return outStr;
}
Greek:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[άΆαΑ]/g, 'a');
outStr = outStr.replace(/[βΒ]/g, 'b');
outStr = outStr.replace(/[γΓ]/g, 'g');
outStr = outStr.replace(/[δΔ]/g, 'd');
outStr = outStr.replace(/[έΈεΕ]/g, 'e');
outStr = outStr.replace(/[ζΖ]/g, 'z');
outStr = outStr.replace(/[ήΉηΗ]/g, 'i');
outStr = outStr.replace(/[θΘ]/g, 'th');
outStr = outStr.replace(/[ίΊιΙ]/g, 'i');
outStr = outStr.replace(/[κΚ]/g, 'k');
outStr = outStr.replace(/[λΛ]/g, 'l');
outStr = outStr.replace(/[μΜ]/g, 'm');
outStr = outStr.replace(/[νΝ]/g, 'n');
outStr = outStr.replace(/[ξΞ]/g, 'x');
outStr = outStr.replace(/[όΌοΟ]/g, 'o');
outStr = outStr.replace(/[πΠ]/g, 'p');
outStr = outStr.replace(/[ρΡ]/g, 'r');
outStr = outStr.replace(/[σΣ]/g, 's');
outStr = outStr.replace(/[τΤ]/g, 't');
outStr = outStr.replace(/[ύΎυΥ]/g, 'y');
outStr = outStr.replace(/[φΦ]/g, 'f');
outStr = outStr.replace(/[χΧ]/g, 'ch');
outStr = outStr.replace(/[ψΨ]/g, 'ps');
outStr = outStr.replace(/[ώΏωΩ]/g, 'o');
return outStr;
}
Swedish:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[åÅ]/g, 'aa');
outStr = outStr.replace(/[äÄ]/g, 'ae');
outStr = outStr.replace(/[öÖ]/g, 'oe');
return outStr;
}
Spanish and Catalan:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[ñÑ]/g, 'n');
outStr = outStr.replace(/[çÇ]/g, 'c');
outStr = outStr.replace(/[üÜ]/g, 'u');
outStr = outStr.replace(/[ïÏ]/g, 'i');
outStr = outStr.replace(/[áÁ]/g, 'a');
outStr = outStr.replace(/[àÀ]/g, 'a');
outStr = outStr.replace(/[éÉ]/g, 'e');
outStr = outStr.replace(/[èÈ]/g, 'e');
outStr = outStr.replace(/[íÍ]/g, 'i');
outStr = outStr.replace(/[óÓ]/g, 'o');
outStr = outStr.replace(/[òÒ]/g, 'o');
outStr = outStr.replace(/[úÚ]/g, 'u');
return outStr;
}
French:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[àÀ]/g, 'a');
outStr = outStr.replace(/[âÂ]/g, 'a');
outStr = outStr.replace(/[éÉ]/g, 'e');
outStr = outStr.replace(/[èÈ]/g, 'e');
outStr = outStr.replace(/[êÊ]/g, 'e');
outStr = outStr.replace(/[îÎ]/g, 'i');
outStr = outStr.replace(/[ôÔ]/g, 'o');
outStr = outStr.replace(/[ùÙ]/g, 'u');
outStr = outStr.replace(/[üÜ]/g, 'u');
return outStr;
}
German:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[Ää]/g, 'ae');
outStr = outStr.replace(/[Öö]/g, 'oe');
outStr = outStr.replace(/[Üü]/g, 'ue');
outStr = outStr.replace(/[ß]/g, 'ss');
return outStr;
}
Slovak and Czech:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[áÁ]/g, 'a');
outStr = outStr.replace(/[éÉ]/g, 'e');
outStr = outStr.replace(/[íÍ]/g, 'i');
outStr = outStr.replace(/[ýÝ]/g, 'y');
outStr = outStr.replace(/[óÓ]/g, 'o');
outStr = outStr.replace(/[úÚ]/g, 'u');
outStr = outStr.replace(/[ôô]/g, 'o');
outStr = outStr.replace(/[ää]/g, 'a');
outStr = outStr.replace(/[ůů]/g, 'u');
outStr = outStr.replace(/[ěĚ]/g, 'e');
outStr = outStr.replace(/[šŠ]/g, 's');
outStr = outStr.replace(/[čČ]/g, 'c');
outStr = outStr.replace(/[řŘ]/g, 'r');
outStr = outStr.replace(/[ťŤ]/g, 't');
outStr = outStr.replace(/[žŽ]/g, 'z');
outStr = outStr.replace(/[ľĽ]/g, 'l');
outStr = outStr.replace(/[ĺĹ]/g, 'l');
outStr = outStr.replace(/[ďĎ]/g, 'd');
outStr = outStr.replace(/[ňŇ]/g, 'n');
return outStr;
}
Polish:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[ąĄ]/g, 'a');
outStr = outStr.replace(/[ćĆ]/g, 'c');
outStr = outStr.replace(/[ęĘ]/g, 'e');
outStr = outStr.replace(/[łŁ]/g, 'l');
outStr = outStr.replace(/[ńŃ]/g, 'n');
outStr = outStr.replace(/[óÓ]/g, 'o');
outStr = outStr.replace(/[śŚ]/g, 's');
outStr = outStr.replace(/[żŻ]/g, 'z');
outStr = outStr.replace(/[źŹ]/g, 'z');
return outStr;
}
Portuguese:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[áÁ]/g, 'a');
outStr = outStr.replace(/[àÀ]/g, 'a');
outStr = outStr.replace(/[ãÃ]/g, 'a');
outStr = outStr.replace(/[âÂ]/g, 'a');
outStr = outStr.replace(/[éÉ]/g, 'e');
outStr = outStr.replace(/[êÊ]/g, 'e');
outStr = outStr.replace(/[íÍ]/g, 'i');
outStr = outStr.replace(/[óÓ]/g, 'o');
outStr = outStr.replace(/[òÒ]/g, 'o');
outStr = outStr.replace(/[õÕ]/g, 'o');
outStr = outStr.replace(/[ôÔ]/g, 'o');
outStr = outStr.replace(/[úÚ]/g, 'u');
outStr = outStr.replace(/[üÜ]/g, 'u');
outStr = outStr.replace(/[çÇ]/g, 'c');
return outStr;
}
Russian:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[аА]/g, 'a');
outStr = outStr.replace(/[бБ]/g, 'b');
outStr = outStr.replace(/[вВ]/g, 'v');
outStr = outStr.replace(/[гГ]/g, 'g');
outStr = outStr.replace(/[дД]/g, 'd');
outStr = outStr.replace(/[еЕ]/g, 'e');
outStr = outStr.replace(/[ёЁ]/g, 'jo');
outStr = outStr.replace(/[жЖ]/g, 'zh');
outStr = outStr.replace(/[зЗ]/g, 'z');
outStr = outStr.replace(/[иИ]/g, 'i');
outStr = outStr.replace(/[йЙ]/g, 'jj');
outStr = outStr.replace(/[кК]/g, 'k');
outStr = outStr.replace(/[лЛ]/g, 'l');
outStr = outStr.replace(/[мМ]/g, 'm');
outStr = outStr.replace(/[нН]/g, 'n');
outStr = outStr.replace(/[оО]/g, 'o');
outStr = outStr.replace(/[пП]/g, 'p');
outStr = outStr.replace(/[рР]/g, 'r');
outStr = outStr.replace(/[сС]/g, 's');
outStr = outStr.replace(/[тТ]/g, 't');
outStr = outStr.replace(/[уУ]/g, 'u');
outStr = outStr.replace(/[фФ]/g, 'f');
outStr = outStr.replace(/[уУ]/g, 'u');
outStr = outStr.replace(/[хХ]/g, 'kh');
outStr = outStr.replace(/[цЦ]/g, 'c');
outStr = outStr.replace(/[чЧ]/g, 'ch');
outStr = outStr.replace(/[шШ]/g, 'sh');
outStr = outStr.replace(/[щЩ]/g, 'shh');
outStr = outStr.replace(/[уУ]/g, 'u');
outStr = outStr.replace(/[ыЫ]/g, 'y');
outStr = outStr.replace(/[эЭ]/g, 'eh');
outStr = outStr.replace(/[юЮ]/g, 'yu');
outStr = outStr.replace(/[яЯ]/g, 'ya');
return outStr;
}
Croatian:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[ćĆ]/g, 'c');
outStr = outStr.replace(/[čČ]/g, 'c');
outStr = outStr.replace(/[đĐ]/g, 'dj');
outStr = outStr.replace(/[šŠ]/g, 's');
outStr = outStr.replace(/[žŽ]/g, 'z');
return outStr;
}
Romanian:
function deLocalize( inStr ) {
var outStr = inStr;
outStr = outStr.replace(/[ăĂ]/g, 'a');
outStr = outStr.replace(/[âÂ]/g, 'a');
outStr = outStr.replace(/[îÎ]/g, 'i');
outStr = outStr.replace(/[şŞ]/g, 's');
outStr = outStr.replace(/[ţŢ]/g, 't');
return outStr;
}