Programmer Isle is a programmer, development-oriented closed zone and instance for use by Blizzard employees and not accessible to players, similar to Designer Island.
Get To Programmers Isle and Designers Isle on Mangos
Ok this can be done using a simple patch that just includes the old map files from previous version of wow when these two places weren't nerfed. Simply place this Patch World of Warcraft->data (or what ever your wow directory is and then data) then open up wow (tested on 2.42, 2.43 but should also work on other versions.) Now To get to the islands type the following GM commands:
Programmers Isle: .go xyz 16304 16318 69 451
Designers Isle: .go xyz 16303 -16173 40 451
Now have fun and do .gm fly on and .mod aspeed 10 and go sick exploring.
PS. Keep in mind only the people with this patch can go there or they will crash so Don't .namego or tele people there. You Can give them the patch they can explore too. For me i gave everybody this patch and there is a bunch of custom events and mazes that are hosted there so use it how you want.