SWFTools is free of charge (donations are welcome, though), and is 
released under the GPL (http://www.gnu.org/licenses/gpl.html).

You can donate via PayPal by clicking on the "donate" button
on http://www.swftools.org/donate.html
.

Download swftools-0.x.x.tar.gz. Then type, on the
command-line:

tar -zvxf swftools-0.x.x.tar
cd swftools-0.x.x
./configure
make 
make install

(you will have to be root for the last step)

You need freetype and jpeglib to compile pdf2swf.
Links:
freetype:
http://www.freetype.org
jpeglib: 
http://www.ijg.org/files/jpegsrc.v6b.tar.gz

In case some of your libraries/include files are installed in /usr/local,
try the following:

rm -f config.cache
LDFLAGS="-L/usr/local/lib" CPPFLAGS="-I/usr/local/include" ./configure

Furthermore, a new installation of jpeglib (the following assumes it's in
/usr/local/lib) often requires doing a

ranlib /usr/local/lib/libjpeg.a
ldconfig /usr/local/lib

In order to install jpeglib, it's furthermore been remarked that you need
to do
make install-lib
make install-headers
.

If it still doesn't work, try removing the file "config.cache"
before running configure again.

Try running configure as

LDFLAGS=-lstdc++ ./configure

You need to get fink (http://fink.sourceforge.net), and install it.
After this, you need to install all the required libs (jpeg, freetype, lame):

fink install libjpeg libjpeg-shlibs freetype2 freetype2-shlibs lame lame-shlibs

Then, you have to inform configure of where they are:

LDFLAGS="-L/sw/lib" CPPFLAGS="-I/sw/include -I/sw/include/lame" ./configure
make
sudo make install

If this doesn't work, especially if you want to use the python library and
get weird exceptions, try to remove all versions of jpeglib, freetype and 
lame from /usr/lib and /usr/local/lib, and then run configure / make / make install
again.

If you also want to use the python interface, you may have to copy the
Imaging headers (Imaging.h, ImPlatform.h, ImConfig.h) to
/System/Library/Frameworks/Python.framework/Versions/2.3/include/python2.3/
before running configure.

Windows versions of all SWF utilities are downloadable from
http://www.quiss.org/swftools/download.html
.
(There's a self-extracting .exe version of all versions since 0.6.1, 
and a .zip or .rar archive of the newest development snapshot)

It's the same as the Unix source code. If you want to compile
under Windows, it's recommended that you get the CVS version
of the sources.
You need MingW (http://www.mingw.org) to compile it.
When cross-compiling under Linux, e.g. the following generates the Windows .exe files:

CXX=i386-mingw32msvc-g++ CPP=i386-mingw32msvc-cpp CC=i386-mingw32msvc-gcc \
./configure --host=i586-mingw32msvc && make

For compiling on Windows itself, there's a HOWTO from Daichi Shinozaki:
http://lists.gnu.org/archive/html/swftools-common/2005-02/msg00023.html

Watch the output of pdf2swf closely.
You should see something like:

WARNING Font Myriad-Roman could not be loaded.
WARNING Try putting a TTF version of that font (named "Myriad-Roman.ttf") into /swftools/fonts

Provided you actually own the font in question (here: Myriad-Roman.ttf), 
you can copy that fonts into your current directory and pass 
the "-F ./" (--fontpath ./) option to pdf2swf. 
If you use a font in several PDFs, you can also simply copy it
to (on Windows) C:\SWFTools\Fonts\, or (on Unix) /usr/local/share/swftools/fonts 
to make it work all the time.

Yes. It supports PNG mode 2 transparency (256 color palettes with alpha) since version 0.4.2. 
Mode 6 (32 bit RGBA truecolor) is also supported since version 0.4.4.

Most tools support the -z flag for outputting compressed SWF.
Furthermore you can compress/uncompress SWF files using swfcombine:

swfcombine -dz file.swf -o file_new.swf

compresses, while

swfcombine -d file.swf -o file_new.swf

decompresses.

Try using the -p (--flip) switch.

First list all extractable items:

swfextract myfile.swf

The result is something like:

Objects in file myfile.swf:
[-i] 3 Shapes: ID(s) 1-3
[-i] 5 MovieClips: ID(s) 4, 5, 8, 10, 12
[-j] 3 JPEGs: ID(s) 69, 116, 447
[-p] 1 PNG: ID(s) 318
[-s] 3 Sounds: ID(s) 28-30
[-f] 10 Frames: ID(s) 0-10

Now you can extract a shape using

swfextract -i 2 myfile.swf -o shape.swf

a sound using

swfextract -s 28 myfile.swf -o sound.wav

a PNG image file using

swfextract -p 318 myfile.swf -o file.png

etc.

Yes there is. You can subscribe by going to

http://mail.nongnu.org/mailman/listinfo/swftools-common

Currently, Matthias is getting much more mails than he can answer. It's frustrating,
but it's true.
He tries his best to at least *read* all mails he receives. 
If you need an answer to something, it's usually more effective to post it on the
mailing list, though, as there are a lot of friendly users around there which may 
have the one or other helpful tip concerning your problem.

Setting deadlines in a non-commercial, spare-time project like swftools tools is hard,
and keeping them is even harder, if not impossible. 

Therefore, do not ask about deadlines, and you won't get fuzzy, or even wrong, answers.

avi2swf isn't part of the swftools distribution anymore. If you want to convert avi files
to swf, please use either mencoder or ffmpeg:

mencoder file.avi -lavfopts i_certify_that_my_video_stream_does_not_use_b_frames \
-ffourcc FLV1 -oac mp3lame -of lavf -ovc lavc \
-lavcopts vcodec=flv:acodec=mp3:vbitrate=500:abitrate=56 -srate 22050 \
-o file.swf

or

ffmpeg -i video.mpg -b -s y -pass 1 -passlogfile log_file video.flv
ffmpeg -i video.mpg -b -s y -pass 2 -passlogfile log_file video.flv
flvtool2 -UP video.flv

Run pdf2swf as usual, and then, on the resulting file, execute:

swfextract -i 3- file.swf -o file.swf

There's a "swfrender" utility in the CVS, which isn't finished yet,
and will only work for *very* simple SWF files. (No Actionscript, no
gradient fills, no morph shapes, no blending modes, no filters, etc.)
Probably other Flash Open-Source projects (like Gnash) have some
more sophisticated utilities for this. (One user reported that
swfdec (http://swfdec.freedesktop.org/wiki/) and pyswfdec 
(http://www.gnome.org/~gianmt) work good)
If you find other tools that work, I'd like to know about it. 
Please mail me at kramm@quiss.org.