While the attiny and esp8266 are very different chips. Both use the same process to setup the Arduino IDE for programming so I'll describe them both here. Basically the way this works is there are open source projects to extend the Arduino IDE to support these additional chips. The Arduino IDE has made itself easily extendable, but you need to tell it where to get these additional chip tool chains and then you need to install them. I am using this solution for attiny and this solution for esp8266.
If you search for these projects you'll fine lots of good setup guides. Here is one I used for attiny and one I used for esp8266. Below are a very basic set of instructions, but if you want a more complete guide check out these links.
- Install the latest Arduino IDE from: https://www.arduino.cc/en/Main/Software
- In the Arduino IDE go to File->Preferences. Add these to "Additional Boards Manager URLs"
- In the Arduino IDE go to Tools->Board->Board Manager. Scroll to the bottom of the list and install the module for attiny or esp8266. The sam3x (SAM Boards) is natively supported so it is in this same list, but near the top. You can figure out where these get installed by looking at verbose compile messages, but for me they went to C:/Users/xxx/AppData/Local/Arduino15/packages/
- Now when you go to Tools->Board there are more board options.
When I release actual devices that require these kinds of updates I'll release more detailed step by step guides.