Conversion functions

Hi, I need to convert from various Asian encoding schemes to UTF8 (3 
japanese character sets, Korean, Chinese, may be Vietnamese and Thai).

Thisi is not for an open source project. I could try to write the functions 
myself but it seems like a daunting task specialy with documents written 
in Japanese only :-). It seems to me that handling all the exception cases 
and escape sequences should be left to people knowing what they do.

Could anyone recommend a commercial product, preferably very small 
footprint.

I know this is not the best place to ask but this is the only Unicode list 
I subscribe to. Thanks in advance.

Nadim.