Comments/Ratings for a Single Item

I am not sure what exactly you have in mind. You want to drag and drop gifs
in an NxM table of checkered background? Without any interpretation of what
happens? Or should it be communicated somewhere?

I have a Javascript script to view a game it downloads from the web.

I should have explained myself better. What I want is a PGN (portable game
notation) which includes fairy pieces and alternative boards. The program
in question creates a Javascript for HTML which can traverse the chess
variant PGN, graphically, on a gif board. There are such generators for
Fide-chess, i.e. which generate the games graphically from PGN. One can
then traverse the game by clicking on a button, or the arrow key. Text
comments will become visible in the mean time.
/Mats

So if I understand you corectly, you want to have a smart program (not
necessarily in Javascript) which is aware of the rules of the variant, so
it can parse PGN (properly disambiguating the SAN moves and taking account
of their implied side effects). This then should pepare an intermediate
format of the game, which can be viewed through a dumb viewer written in
Javascript.

Sounds very close to what I already have, and was using in my 'Battle of
the Goths' Championships. ( http://home.hccnet.nl/h.g.muller/goths.html ) I use WinBoard as the smart PGN parser, which then prepares a data file
that is loaded by the Javascript-powered HTML page, and unambiguously
specifies how the latter should juggle around gif images to replay the
game.

Only thing that is missing is buttons to scroll through the game, just one
to replay it completely from the beginning. But I guess that would be a
comparatively simple addition.

Oh, you have already begun the work. Good, then you can continue improving
it.

No, there needn't be any rules checking. The PGN parser could accept
anything, e.g. 5.Xg1-c7. In this way all variants are supported. It would
be great to have such a tool. Then people could begin to analyse chess
variants, using text comments. In the PGN header one must introduce a
board-type tag (e.g. BOARDTYPE 5). See the PGN standard here:
http://www.tim-mann.org/Standard
The chess variant PGN standard would accept M, X, Z, R, etc., as piece
denominators. One needn't have special gifs for every piece. One could
have generic gifs, too.

The program should be open license so that people also can use it for
commercial purposes (e.g. create chess variant CD:s).
/Mats

The WinBoard move parser actually does accept a very wide range of move
notations, and Xa1-b2 is one of those. This is fine in 'perfect' Chess
variants like Shatranj, Xiangqi, and Shogi, where the only capture is
replacement capture, and moves never have side effects. But in FIDE Chess
there ae already problems with castling and e.p. capture: somewhere along
the line from PGN to display it should be known that Ke1-g1 means that a
Rook should be moved as well, and that on e5xf6 a Pawn should be removed
from f5.

In the ChessLive! viewer I solved those problems by recording such moves
in the intermediate format as multiple move: in general a move can consist
of multiple (fromSquare,toSquare) pairs, and for 0-0 I write, say,
e1g1h1f1, and for e5xf6 e.p. I write e5f5f5f6 (or f5f6e5e6). This can keep
the viewer totally dumb.

But you can't expect that information to be present in the original PGN.
it seems that you have a different concept of PGN from what it really is
already: you would not find a move like Xa1-b2 in any PGN file, as PGN is
supposed to use Standard Algebraic Notation (SAN), which would list the
move as Xb2. Or, if there are multiple X on the board that could move to
b2, like (preferably) Xab2 or X1b2. I guess in theory Xa1b2 could occur, if
there are three pieces of type X, located on the intersections of two files
and two ranks (e.g. Na1, Nc1, Na5) that could all go to the same square
(b3). So it could occur even in FIDE Chess. But I have never seen it
happen. So in SAN normally a full specification of the from-square is
absent, even if the instance gnerating the SAN is totally unaware of how
the pieces move, so that it has to add a disambiguating rank or file
indicator for every move with a piece of which there are multiple copies on
the board. This puts the burden on the SAN parser to keep track of the
board state, so that it knows where each piece of a given type is located.

Anyway, the sitution in WinBoard is that it currently supports 22
different piece types (for both black and white), that you can assign any
letter to. If you switch legality testing off, the pieces can move any way
you want. (With legality testing on, it has a pre-programmed notion of how
every piece should move.) Each piece has a standard pictogram
representation on the screen, but this can be overruled as well by
user-provided graphics. Board size is adjustable, but in practice the SAN
parser does not work beyond 12x10 yet (e.g. it does not understand
double-digit rank indicators).

PGN defines a variant tag (e.g. [Variant 'xiangqi']). The WinBoard
convention for variant naming is such that you can use non-standard board
sizes by prefixing them to the variant name, and that a catchall name
'fairy' is defined, where every piece can partcipate. So you could
specify 6x6_fairy for a mini-variant on a 6x6 board including Elephants and
Achbishops, or even 6x6+4_fairy if it was a Shogi-like variant with piece
drops and holdings for 4 piece types.

Long PGN is accepted in all chess databases. You can  verify this by
copying and pasting the below into ChessBase, for instance.

1.Pe2-e4 Pe7-e5
2.Ng1-f3 Nb8-c6

In an expanded PGN on can have additional header tags which can turn off
castling and e.p.
[CASTLING 0] would mean turn off castling. Castle-on is default.

I find it inexplicable that so few people think it worthwhile with a chess
variant PGN viewer for HTML. Such viewers are used everywhere on the net
for Fide-chess. It would greatly enhance the analytic aspect, since people
are almost only involved in inventing variants. With a viewer, they can
begin to analyse them. This is also the first step to a chess variants
database.
/Mats

What I don't fully understand is why you stress that it should be HTML and
JavaScript. Perhaps because I don't fully understand how you envision this
to be used.

When I encounter a PGN game somewhere (as text on a web page, or as a
downloadable .pgn file), I always view it with WinBoard (by pasting it in,
or loading it from the downloaded file). Then you have all the
functionality you say: you can step through the game, while viewing the
comments, edit the game by adding or deleting moves at the end, add
comments to it, or edit the exsting comments, save the (edited) game on
file, or copy it (or the position) to the clipboard, save positions as a
diagram on a bitmap file.

Plus you can do more, as it is also possible to have an engine analyze the
positions in the game, and show its scores and PVs in a separate window. I
always have a WinBoard shortcut on my desktop to quickly start it up when I
need to view PGN.

I don't see how HTML would add anything to this. The reason I made the
JavaScript viewer was to allow people to follow games live with a browser.
It was never meant as an analysis tool.

BTW, the castling tag is not really needed, absense of castling could
simply be indicated in the FEN for the initial position.