I suspect this will be a short lived project, because the original project team will hopefully refactor their repo ,(http://github.com/esp8266/arduino) to address the need to download a custom version of the whole of the Arduino IDE.
I have created a github repo which allows programming of the ESP8266 using the stock Arduino 1.6.x IDE (older 1.5.x versions should also work).
I did this for 3 reasons.
1. The current version of the downloadable release (containing Arduino 1.6.1-p1) doesn’t work for the ESP8266, as there appears to be an issue with the compiler not being able to find the file libiconv-2.dll. (This can be fixed by copying this file from the AVR folder to the root of the folder, e.g. where arduino.exe is located. )
2. There is no need to download the entire Arduino IDE
3. Arduino 1.6.1 has been superseded by 1.6.2 and its likely that a new version e.g. 1.6.3 could be here in a matter of weeks, hence needing to keeping the ESP8266 Arduino IDE installation up to date will be problematic.
And there is a better solution.
My repo uses the same principals used in the Arduino_STM32 repo, where the main Arduino IDE does not need to be changed and the whole of the IDE does not need to be downloaded.
All you need to do is download the zip from Github https://github.com/rogerclarkmelbourne/arduino-esp8266/archive/master.zip and unzip it into your My Documents/Arduino/hardware folder
If you don’t already have a hardware folder in My Documents/Arduino, simply create a new folder (and rename it to hardware)
Once you’ve unzipped the file. Restart your Arduino 1.6.x ide and select Generic ESP8266 from the Boards menu, and select esptool from the Programmers menu.
The current version uses V0.9 of the ESP SDK, not 1.0, however either the original project team will update this or I will try to update to 1.0 if I have time.
One other thing, I”ve noticed is the esptool.exe used to upload the 2 bin files, doesn’t seem to give an error message if the upload fails part way though the transfer. So if after uploading, your new program doesn’t seem to work, the best option is to reset the ESP8266 and upload again.
(See the readme on github for more details https://github.com/rogerclarkmelbourne/arduino-esp8266/blob/master/README.md )