upTeX is an extension of pTeX, using UTF-8 input and producing UTF-8 output. It was originally designed to improve support for Japanese, but is also useful for documents in Chinese and Korean.

It can process Chinese simplified, Chinese traditional, Japanese, and Korean simultaneously, and can also process original LaTeX with \inputenc{utf8} and Babel (Latin/Cyrillic/Greek etc.) by switching its \kcatcode tables.

The author is Takuji Tanaka.