It reached 4d on kgs server (account Pachi2 cluster version)
See latest go software updates for the latest update news.
Homepage is at http://pachi.or.cz/.
Online webapp http://www.peepo.com with maps and comments as you play please use latest Firefox or another standards-based browser, in case of difficulty.
The source code, written in C, is available at http://repo.or.cz/w/pachi.git.
Windows binaries (include Makefile for MinGW) are downloadable at http://pachi.or.cz/.
The successive versions of the program are named after famous Japanese players: