So Shockwave was often used for more complex applications than Flash. Flash was for 2D animations and simpler games, Shockwave perhaps for 3D. But maybe they were separate, and later Adobe combined some features. I should check that.

Also, consider the security issues: Like Flash, Shockwave had vulnerabilities that led to its discontinuation. Mention specific instances if possible, but maybe not necessary in a general post.

Now, start drafting each section with these points in mind.

In the decline section: The rise of HTML5, JavaScript, WebGL made plugins like Shockwave obsolete. Security issues were a big problem. Also, the shift to mobile where plugins didn't work. Adobe's announcement to phase out Shockwave, same as Flash, due to security and performance issues.

Need to make sure to correct any inaccuracies. For example, confirm that Flash and Shockwave were separate products from Macromedia, with Flash focusing on 2D and Shockwave on 3D. Adobe bought Macromedia in 2005, then maintained both, but eventually both were sunsetted.

Include some statistics: How many users used it at peak? Not sure if exact numbers exist, but maybe compare to Flash's usage.