I want to program my arduino via wifi, but the only guide i could find is using Bluefruit EZ-Link, but I am not... Im using an ESP8266.
Please HELP!!
You cannot as far as I know. You can however program the ESP8266 via wifi.
OK, Ill just put my raspberry PI there
Some time ago I did a modification of Markus Sattler's HTTPClient class update example, to do on demand pull type updates for Itead Nextion displays. Very simply you hit a key on the display, triggered the function on the host ESP8266, ESP gets the file stream from remote location and squirts to Nextion using the required chunk protocol.
All very seamless, and simple for end users.
Doing something similar for Arduino updates should not be too difficult.
The STK500 protocol is published and available.
The idea begs the question though, why not run your host application on ESP8266? Then you have access to all manner of OTA update methods.
Unless of course ESP does not have enough GPIO for your application:(