GIB, NGF, and UGF/UGI converter to SGF for the game of Go / Baduk / Weiqi.
GIB and NGF work well; UGI probably less so.
If you run into encoding problems (i.e. player names become gibberish) try editing the encoding settings at the top to match your input files. For example, Chinese GIB files may be encoded as GB2312. (Yeah, this is a lame way to handle this, sorry.)
Github user y-ich made a Node JS version of this: https://github.com/y-ich/xyz2sgf