There have been so many updates over the past 2 weeks that they won't all fit onto a single page. Here are the pure chess-related updates

Engine Updates

Arabian Knight 1.51 (WB)
Java source; own GUI; mp
http://wbec-ridderkerk.nl/html/details1/ArabianKnight.html (Leo site)

Jim Ablett Win/Linux builds
Arabian Knight 1.51 JA (WB)
Win 32/64; Java source; mp
http://jim-ablett.co.de/

BagaturChess 1.2a (UCI)
BagaturChess 1.2b (UCI)
Java source; Win32/64; mp
1.2a:
- 50 ELO stronger than version 1.2. Achieved by tuning of search algorithm
- min threads count of SMP version are set to 2. Reported by Olivier Deville during OpenWar 9th Edition test games
- default process priority is set to 'normal'
- technical: Refactoring of configuration API; Impl code
1.2b:
- bugfix: read and use the option set for threads count of SMP version
http://sourceforge.net/projects/bagaturchess/

Bearded Neural 44.1 (WB)
Win32
- added book learning
http://brodacz100.republika.pl/download.html

Butterfly 0.3.3 Win64 (WB)
C++ source; Win32/64, perft with source also available
http://code.google.com/p/butterfly-chess-engine/downloads/list (new homepage)

Jim Ablett Win/Linux builds
Cheng3 1.05 JA (UCI)
Win 32/64
http://jim-ablett.co.de/

Chess One 4.x, build Nov 4 2011 (WB)
Win32, Linux32; own GUI (echoboard GUI, actually)
http://serg-nifont.narod.ru/chess_4_x.html

Chiron 1.1 (UCI)
commercial, FRC, Win32/64
http://www.chironchess.com/

CuckooChess 1.12 (UCI)
Java source; Android; own GUI; uses Cuckoo hashing
- "+61 Elo"
http://web.comhem.se/petero2home/javachess/index.html (homepage)
http://web.comhem.se/petero2home/javachess/ChangeLog.txt (changes)

Jim Ablett Win/Linux builds
CuckooChess 1.12 JA (UCI)
Java source; Win 32/64
http://jim-ablett.co.de/

DoubleCheck 2.0 (UCI)
C source; Win64, Linux64
"it scored +110 elo against [previous] version"
- improved evaluation:
--- it understands unstoppable passed pawns when the opponent has no pieces
--- passed pawns are incentivised, especially connected passed pawns, and especially as there are few pieces on the board and the passed pawns are advanced
--- understands doubled, isolated, chained, backward pawns
- ability to handle fixed depth search, fixed number of nodes, or infinite search
- bug fixed on the time allocation, which could cause DoubleCheck to lose on time. Now it should never lose on time, provided the UCI interface is not lagging
http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html (Leo page)

EnginMax 5.20 (UCI)
Win32/64
- some more bugs fixed, changes in search, sorting moves, futility pruning
http://sites.google.com/site/mychessengines/files

Francesca MAD 0.19
Win32; hash fixed in size: 24MB(diet), 128MB(standard), or 1GB(lardy)
"an improvement of around 30 Elo"
- use a score "scaling" feature between the middle and endgame
- 'diet' version resurrected
http://www.zen55564.zen.co.uk/download.htm

Frenzee 3.5.19 (WB/UCI)
Win32/64; SMP, Linux; FRC
NOTE: homepage requires installation of non-standards-compliant Microsoft
Silverlight software; Microsoft now uses HTML5 + JavaScript instead of the
old, deprecated Silverlight product
http://www.computerskak.dk/

Ivanhoe 999947d (UCI)
C source; Win32/64; Ippolit derivative
- this is a 'PeterPan' build
http://ippolit.wikispaces.com/Ivanhoe+B47d.rar

Komodo 3.0 (UCI)
Win32/64, Linux32/64, Mac; own GUI
- added own GUI (Tarrasch Chess GUI, actually)
http://komodochess.com/

ProDeo 1.7 (WB)
Win32
"should give the Benjamin [latest] version of ProDeo a good elo jump"
"Make sure you get the 1.71 personalities"
- tuning
- activating various settings already present in previous versions
- a more modern search approach collected in several personalities
http://www.top-5000.nl/prodeo17.htm

Quazar 0.3 (UCI)
Win32/64
- website estimated Elo increased by 200 points
https://sites.google.com/site/chessquazar
http://www.sdchess.ru/download_engines.htm (alternate download site)

Sjaak r263 (WB)
C source; Win32/64, Linux32/64, Mac32/64; variants
http://www.eglebbk.dds.nl/program/chess-index.html

Strelka 5.1 (UCI)
Win32/64
http://translate.google.com/translate?js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fstrelkachess.narod.ru%2FStre...
http://www.sdchess.ru/download_engines.htm (alternate download site)

Supra 6.1 (UCI)
Win32
http://suprachesssystem.com/ (English)
http://www.suprachesssytem.com/ (Portugese)

Tornado 4.82 (UCI)
FRC; multi-pv; mp, Win32/64; limit strength
- after allocation of hash more then 2 GB crashed, this is fixed now and it can use more hash in 64 bit, tested with 4 GByte hash on my hardware
- material hash table added, a slightly improvement in eval for material count
- different bugs fixed, especially the time bug for x moves in y min
- slightly speed improved with PGO compilation
http://sites.google.com/site/mychessengines/

Zeta Dva 0.204 (WB)
C source; own GUI; Linux64; supports Polyglot books
"less nps, more ply, better play"
- added Futility Pruning
- added Razoring
- mod in LateMoveReductions, more agressive
- mod in time control, clock based
- fix in Evaluation for blocked Pawns
- fix in TT-Move
- fix in Matescores/KRk-Endgame
https://github.com/smatovic/zeta_dva
https://github.com/smatovic/zeta_dva/tree/zeta_dva_0204/bin (Linux64 direct link)

Jim Ablett Win/Linux builds
Zeta Dva 0.204 JA (WB)
C source; own GUI; Win32/64, Linux32/64; supports Polyglot books
http://jim-ablett.co.de/

Chess News

Chess Engine Logos 1.76
Jim Ablett Logo Collection
http://jim-ablett.co.de/ (scroll to bottom)

Bihasa_2.0 (WB)
variant engine for playing Capablanca and Gothic Chess on a 10x8 board size
by Deuterium author Ferdinand Mosca
http://sites.google.com/site/deuteriumengine/downloads-1

Chess Engines for Android
- GreKo 8.2
http://www.aartbik.com/MISC/eng.html

Chess for Android 3.0.2 (WB/UCI)
Aart Bik's free gui + chess engine for the Android phone
- enhances XBoard/WinBoard support (infinite analysis, resign feature, older idioms used by various engines)
http://aartbik.blogspot.com/
http://www.aartbik.com/MISC/android.html

CLOP page
(for engine programmers only!)
CLOP helps tune parameter values
- CLOP page updated with pdf slides
http://remi.coulom.free.fr/CLOP/

JavaPairing 2.2
open source cross-platform chess pairings manager for Swiss events
http://sourceforge.net/projects/javapairing/ (project page)
http://javapairing.sourceforge.net/ (homepage)

Lantern Chess 4.54 (WB/UCI)
Chess GUI by Mike Adams supporting WB & UCI for ICC online play/chat for Linux, Windows and Mac
http://www.lanternchess.com/ (homepage)
http://www.adammr.com/lanternhelp/lantern-help.html (help)

Olivier Deville's PGN collection
also a Polyglot book based on the 46,999 PGN games
"Games from 2001 to 2011"
- minimum Elo = 2530
- only long time control games
- no annotations
- no computer games
- no games under 20 moves
http://www.open-aurec.com/chesswar/download.html

Penguin 7.1
PGN Editor for Chess and limited functionality UCI interface
"Penguin can interface with UCI engines and suggest best moves for game positions"
http://myweb.tiscali.co.uk/dashstofsk/penguin.html

Norm Pollock site
PGN & EPD Utility Suites and Opening Book PGN Databases
- EPD program update: merged epd
- EPD program update: merged pvOpcode into bmOpcode
- EPD program update: epdTrim, bmOpcode
- EPD program removal: cnOpcode, epd
http://www.hoflink.com/~npollock/chess.html

Xboard 4.5.3 Installer for Mac
new update compiled by 'Darklord42'
http://www.open-aurec.com/wbforum/viewtopic.php?f=19&t=50428 (forum post)
http://www.mediafire.com/?9cg7lf31u58b5vo (direct link)

Down/Problem Chess Websites

Asterisk homepage down today
Damas homepage down for 40 days ("Free Web Hosting Discontinued")
Dann Corbit homepage down for 130 days
Safrad homepage down today (no response in 60 seconds)
Smash homepage down today (website configuration problem)
Vicki homepage down today (no response in 60 seconds)
Waxman homepage down today (no response in 60 seconds)
Ildtiadar homepage is now considered dead, it will no longer be tracked.

Wiki Changes

Chess Engine List
- removed Ildtiadar
http://computer-chess.org/doku.php?id=computer_chess:wiki:lists:chess_engine_list

FACE Tournament
- Gerhard continues to update his tournament site with recent results
http://computer-chess.org/doku.php?id=computer_chess:tournaments:face

GUI Protocol List
update by Norbert Raimund Leisner
- added Java Chess Protocol Interface
- added sPYderchess
- Winboard 4.27: updated comments
- Winboard: added more links
http://computer-chess.org/doku.php?id=computer_chess:wiki:lists:gui_protocol_support_list

Links
update by Norbert Raimund Leisner
- updated two Jim Ablett links
- added ELOcalc
- added Chess Tournament Management
- added Php Chess Tournament Manager
http://computer-chess.org/doku.php?id=computer_chess:wiki:links

Macintosh Engine List
update by Norbert Raimund Leisner
- added Ajedrez
http://computer-chess.org/doku.php?id=computer_chess:wiki:lists:macintosh_engine_list

Mobile Chess List
update by Norbert Raimund Leisner
- added Dark Knight for Android
http://computer-chess.org/doku.php?id=computer_chess:wiki:lists:mobile_chess_list

PGN Reader/Viewer/Writer List
update by Norbert Raimund Leisner
- added PGN-Extract GUI Interface
- added Chess Diagram Editor
http://computer-chess.org/doku.php?id=computer_chess:wiki:lists:pgn_reader_viewer_writer_list

Private Engine List
update by Norbert Raimund Leisner
- removed Deep Noob, it has not been active for a long time
http://computer-chess.org/doku.php?id=computer_chess:wiki:lists:private_engine_list

Retreated Engine List
- added Ildtiadar
http://www.computer-chess.org/doku.php?id=computer_chess:wiki:lists:chess_engine_list#retreated_engine_list

Source Code Only List
update by Norbert Raimund Leisner
- removed Deep Noob
http://www.computer-chess.org/doku.php?id=computer_chess:wiki:lists:chess_engine_list#source_code_only_list