PlayStation Developer Wiki's History
The PSDev Wiki Started off as the PS3Dev Wiki which is owned by defyboy, the PS Vita came along and SKFU asked me(GregoryRasputin) to create a Dev Wiki for it, so i did and this was my first venture into owning a Developer Wiki, the VitaDev Wiki did not belong to the PS3Dev Wiki and was more like a smaller sister, then the PS4 came along and defyboy decided to drop the PS3Dev Wiki URL and bye the PSDev Wiki URL, which saved money as all future Wiki's would now be under the one URL.
I still had the Vita Dev Wiki which was registered under vitadevwiki.com and it was requested by Mathiuelh that a PSP Dev Wiki be created and that was added under pspdevwiki.com, then a year after the PSPDev Wiki was created zecoxao requested that i create a PS1 and PS2 Dev Wiki and that is what happened, i then decided to buy playstationdevwiki.com and put all the Wiki's i owned under that domain.
psdevwiki and playstationdevwiki are owned by different people, but they are still related to each other, think of psdevwiki as the bigger sister of playstationdevwiki, if that is too confusing, then think of psdevwiki as the home for the PS3, PS4 and future PlayStation Home Console Dev Wiki's and think of playstationdevwiki as the home for Handheld and Retro PlayStation Dev Wiki's.
This is a basic explanation as to why there are two PlayStation Developer Wiki's.