
Re-release of v2.0.2 with Release builds (the prior download had Debug build SWF files)

SWFUpload v2.0.1 represents the most complete build of SWFUpload to date. It includes several bug fixes, API improvements and both Flash Player 8 and 9 versions.
This is the first version that allows developers to target Flash Player 8 or 9. This gives developers greater compatibility or a greater feature set depending on a project's need.
v2.0.1 is based on the Revision 7 code-base with several bug features, a few API changes and greater functionality. Great lengths have been taken to work around limitations in the current Flash Players providing developers with a consistent and stable platform for handling file uploads.
v2.0.1 also introduces several SWFUpload plugins. These provide some of the most asked for features that don't fit in the core SWFUpload code base. These plugins include (or will soon include ) Graceful Degradation, Cookie passing, SWFUpload v1.0.2 Compatibility, DocumentReady, and Flash Detection Kit. The plug-ins are a work in progress and contributions are welcome!

SWFUpload version 5.2 source and demos.

6.2 branch of SWFUpload.

If an upload is cancelled after the progress has reached 100% but before the upload script has finished processing then SWFUpload blocks until the upload script has completed. uploadComplete and fileComplete are still called along with uploadError. I'm still working out the best way to handle this situation (and have received some very good ideas in the comments).
To avoid this issue don't use the cancel feature or track your file progress in the JavaScript and prevent cancel calls to 100% still processing files. The issue will be fixed before the final 7.0 release.
You can test this by performing a long running process in your upload script. In PHP I tested by adding a sleep(30) statement. This causes SWFUpload to progress to 100% and then pause for 30 seconds while the upload script sleeps.

Official SWFUpload v1.0.2 release by swfupload.mammon.se
The source distribution contains all the source files and a FlashDevelop project for the .as-class. SWFUpload is developed in FlashDevelop so there is no .fla file, and it is compiled with an opensource actionscript compiler.