The Windows XP source code was allegedly leaked online

[atom0s]

Originally Posted by nulli

The Windows XP/2003 source is a nice addition to the collection. But these days its really not a big whoop if you have the Windows 2000+WRK sources. You can use the XP source to get some more hints about how something used to work. Which can help a bit. But there is a lot of internals that have changed in Windows 10 especially.

Would say this is more useful towards targeting XP, Vista, and 8 machines along with the server 2k3/2k8 versions for 0days and other exploits. Having the raw source makes it a lot easier to find/track down certain types of exploits vs. just using decompiled information and pdbs as well.

Some stuff is still reused from XP to 10 as well. Graphics related information, some drivers and kernel-level stuff etc. are still similar/the same across every version.

Would also be something more useful to locations such as China who are still a majority user of Windows XP, along with creating their own Windows XP clone OS. This is probably a big deal to them and of interest to them (not to really say they didn't already have this code anyway though).