FlashDevelop got a rave review from us back in August. The final version was released today with full MXML and AS3 support.
FlashDevelop is a complete Flash authoring solution that is such a productivity booster that we cannot praise it enough. It's free, snappy, solid, Open Source, in active development and it now integrates with the Flex SDK. If you primarily work with Actionscript , you should really check it out as it will save hours just from reduced compile time.

This version adds full AS3 code completion, MXML completion and Flex 2 compiler integration. The setup still requires a bit of manual setup, but it's nothing difficult. If you want to automate your build environment, Keith Peters has recently published ANT templates to get you started. Using ANT can save you a lot of time recompiling projects consisting of multiple SWF files.

SWF Encrypt™ 3.0 encrypts your Adobe (Formerly Macromedia) Flash® SWF files, protecting them from the most popular Flash Decompiler Tools on the market! Secure your ActionScript today and prevent SWF Reverse Engineering and Decompiling

SWF to FLA Converter for PC is a new tool to convert any Macromedia Flash file to the original FLA. Thanks to it, you can customize any file available on the Internet (providing that you don't abuse copyright notes) to suite your needs.

SWF to FLA Converter uses innovative technologies to recreate all compiled Flash objects (shapes, sprites, morphs, ActionScripts, components and so on) and place them to separate layers on the FLA's timeline. The highest degree of conversion accuracy can be achieved by tweaking and customizing various options provided by our Converter, making sure that you will be satisfied with the result.

SWF to FLA Converter automatically defines the version of original SWF file and converts it to the same version of FLA, however, you may change the version at the will. Incomparable usability and features provided make SWF to FLA Converter the best Flash decompilation software on the market

Unique SWF conversion algorithms make this program the most reliable and fastest way to restore original FLA from SWF
Over 50 options available to extract sounds, images, videos, shapes, frames, morphs, fonts, texts, buttons, sprites and ActionScripts with the great accuracy
Flash 8 and ActionScripts 2.0 are supported
Provides ability to extract every object into a separate layer
Group SWF objects (text/motion/sound/ActionScripts, etc.) into a separate library entry for better representation
Specify folder's name for each FLA library
Sophisticated morphs conversion algorithms are supported to ensure that all frames are correctly extracted
Convert many broken or incorrectly compiled SWF files
Customize resulting FLA project to suite your needs (enable/disable grids, guides, advanced snapping options, etc.)
On-screen detailed conversion parameters description
Professionally selected default conversion settings helps you achieve the best results
Easy-to-use interface with intellectual, fully customizable controls

FlashCommand.exe -e | -c | -p [-q] [-v] [-x] [-q] (-s <sourcefile>) ([-l] [<logfile>])
([-o] <exportpath>) ([-f] <flashpath>) ([-t] <timeout>)

-version : Prints out information about the program.
-help | Prints out usage information.

-e : Specifies export action.
-c : Specifies save and compact action.
-p : Specifies publish action.

-l : Specifies whether output should be logged to a file. Optional. Takes an optional
param specifying the path to the log file. If not specifies, log files will be
place in \log
-q : Specifies quite mode. Optional. If specified, no output will be written to console
(although it may still be logged).
-v : Specifies verbose mode.
-d : Specifies temp directory that will be used for temporary file.
-s : Specifies source files. Required.
-o : Specifies the output file if -e flag is also set. Optional. If not specifies,
file will be output to same directory as source.
-x : Specifies whether Flash should be closed after it is done processing. Optional.
-k : Specifies whether the temp jsfl file should be deleted. Optional.

-f : Specifies Flash executable path. Optional.
-t : Specifies timeout value. Optional
-d : Specifies temp directory. Optional.

Apollo is a cross-OS runtime that allows developers to leverage their existing web development skills (Flash, Flex, HTML, Ajax) to build and deploy desktop RIA’s.

With more than 1,200+ functions available, Janus crushes even it’s closest competition by 50%. That’s because Janus was built to tap into the the raw power, wealth of functions, and the rock solid stability provided for in the .NET Framework 2.

Create pdf files directly from actionscript, integrate your application with GPS technology, embed instances of Internet Explorer, Acrobat reader, or Mozilla firefox, record sound, compose, play and save MIDI files…

secureSWF protects SWF files from decompilers and reverse engineering. It provides the most advance Flash ActionScript obfuscation, optimization, and encryption making secureSWF the unquestioned market leader.

Sothink SWF Decompiler 4 supports Flash CS3 (9.0) and ActionScript 3.0 completely. It can convert SWF to FLA and extract elements from SWF into variable formats. Compatible with all Flash versions including Flash 6, Flash 7, Flash 8 and Flash 9. It also supports both ActionScript 2 and ActionScript 3. After the converting, you can get the completed FLA file including linkage, components, .as, etc. A free SWF catcher tool is also provided

...a handy solution for web-masters, web-designers, Flash professionals and everyone who has ever come in touch with Adobe Flash technology. It can reduce your SWF files size up to 60-70% thanks to advanced algorithms of vectors, shapes, morphing, Z-buffer, fonts, embedded video and other optimizations. Unlike any other similar software Flash Optimizer manages to optimize not only a separate part of your Flash movie, but the whole SWF, including curves, zero-objects, applying ZLib optimization and many other advanced techniques