irrFuscator is an ActionScript obfuscator. It protects .SWF files as well as .AS and .MXML files, no matter if you use Flash or flex. irrFuscator is available for the command line but also comes with a convenient GUI frontend. It is able to encrypt strings, obfuscate method, variable and class names, strip whitespace, does nondeterministic obfuscation and automaticly detects references to external flex code.

The ActionScript 3 Byte Code (abc) in .swf files still contains a lot of symbols revealing how your program works and what it does, so it is very easy to reverse engineer or steal your code. irrFuscator can be used in two modes:
SWF Obfusction (Binary): protects an existing .swf file.
Flex Obfuscation (Source): reads in a directory of .as and .mxml files, processes them and puts them out into a target directory. Simply recompile the directory with the obfuscated files and your .swf files are a lot safer.

• SWF Protector 3.0
  SWF Protector is the software that is aimed to help Flash developers protect the unique ActionScript code of their SWF files and their intellectual property accordingly. It is...

• SWF Protector for PC 4.0
  Most of Flash developers and webmasters want to protect their Adobe SWF files from unauthorized use, but it becomes more and more difficult because of the different decompiling programs

• SWF Decompiler for Mac 5.0
  SWF Decompiler for Mac is an essential SWF to FLA and Flex projects conversion tool. You can easily decompile SWF on Mac and convert SWF files back to their source formats: FLA or Flex project files (depending on how original SWF file was compiled)....

• toKaos 1.3.5
  toKaos is a desktop software application which allows you to encrypt/obfuscate your Flash/Flex AS3 application protecting your work from SWF/SWC decompilers