SWFUpload to be Removed from WordPress
WordPress 4.9 will remove the SWFUpload open-source library from core. Will that affect the total amount of External Libraries? surprisingly not!
SWFUpload is an open-source library that allowed developers to use Flash player’s upload functionality to upload multiple files, display upload progress, check file size from the client-side and had a set of event handlers for developers.
The library provided handful tools for developers, while allowing the developer to use his own UI for the upload (HTML/CSS).
SWFUpload and WordPress
Many popular project used SWFUpload for file uploading, including WordPress and YouTube. WordPress used SWFUpload until the development of the library was stopped. But WordPress forked the library and maintained the code by fixing security issues.
In WordPress 3.3 the Flash uploads replaced with JS uploads, switching from SWFUpload to Plupload. But WordPress continued to bundle the library for plugins and themes that didn’t migrate to Plupload.
Removal from Core
Although WordPress stopped using SWFUpload over 6 years ago, it seems like there are several popular plugins and themes that are still using this Flash based library.
WordPress 4.9 will remove the library files from core. Plugins and themes are asked to migrate to Plupload library or include their own files instead of using the files in WordPress core.
External Libraries Stats
Even though SWFUpload files included in core, the library didn’t received credit because it was not used by core. Therefor the current files removal will not affect the total amount of external libraries in the credit page.