SWFTools

If you're looking for a comprehensive SWF manipulation and creation toolkit, then you may want to check out SWFTools by Rainer Böhme and Matthias Kramm. With this software, you are given a variety of utilities that allow you to modify and create SWF files with ease. The best part is that the project is released under the GPL, meaning that it is open source and free for anyone to use.

But that's not all. SWFTools has a proven track record of working on a wide range of operating systems. You can install and use SWFTools on Solaris, Linux, FreeBSD, OpenBSD, HP-UX, MacOS X, and even legacy operating systems such as Windows 98, ME, 2000, and XP. This cross-platform compatibility makes SWFTools a great choice for those who need a tool that will work across multiple devices and platforms.

Overall, SWFTools is a reliable and versatile set of SWF manipulation and creation utilities that is definitely worth checking out. Whether you're an experienced designer or a beginner just starting to learn about SWF files, you will find the tools within SWFTools to be intuitive and easy to use. With its open-source license and broad compatibility, this software is definitely one to consider.