Macromedia Flash MX was also the first version released after Adobe started running scared and fighting dirty with a look-and-feel lawsuit against Macromedia Flash 5 for its use of tabbed UI palettes: https://web.archive.org/web/20010516014855/http://www.adobef...

“Adobe's tabbed palette, used throughout Adobe's products, are being copied by Macromedia® in many of its products, including Macromedia® Flash™ 5, Dreamweaver®, FreeHand® and Fireworks® software.”

Compare the infringing tabbed palettes of Flash 5 to the non-infringing (vertically-stacked) palettes of Flash MX:

- https://www.webdesignmuseum.org/old-software/macromedia-flas...

- https://www.webdesignmuseum.org/old-software/macromedia-flas...

And then of course Adobe gave in and bought Macromedia outright in the MX2004 era.