There are some Russian documents on this page.
Binkd cannot (and never will) make calls via regular telephone lines, so it should be used not instead of, but along with any other Bink-style Fidonet mailer. It's known that Binkd (at least) runs perfectly together with Ifmail, Brake!, Bink/+, McMail, T-Mail and Xenia mailers.
Binkd comes in ANSI C sources, so it can be built in almost any environment with Berkeley sockets API supported (multitasking is a plus). I know about UNIX (AIX, FreeBSD, NetBSD, Linux, Solaris), OS/2, NT, DOS, and Windows'95 ports.
(new) Right now (2000/06/13) I don't develop binkd (though I do read BINKD-DEV mailing list), and all the official versions of binkd past 0.9.3c are released by Pavel Gulchouck and the team of BINKD-DEV. You can get current binkds from ftp://happy.kiev.ua/pub/fidosoft/mailer/binkd/. I'll try to mirror all the releases here.
Binkd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation.
cvs -d :pserver:email@example.com:/cvs co binkd
Binkd User's Guide (english) by Nick Soveiko.
Thanks to all these people, who ported Binkd, patched it, or helped Binkd project in other ways. (Please, excuse me, if I forget someone!)