Added link to alpha builds

Author: cmaglie

README.md

@@ -12,9 +12,19 @@ It will be soon used as a building block in the Arduino IDE and Arduino Create.
 
 ### Download the latest stable release
 
-This is not yet available until the first stable version is released.
+This is **not yet available** until the first stable version is released.
 
-### Build from source
+#### Download the latest unstable "alpha" preview
+
+Please note that these are **preview** build, they may have bugs, some features may not work or may be changed without notice:
+
+- [Linux 64 bit 0.2.0-alpha.preview](http://downloads.arduino.cc/arduino-cli/arduino-cli-0.2.0-alpha.preview-linux64.tar.bz2)
+- [Linux 32 bit 0.2.0-alpha.preview](http://downloads.arduino.cc/arduino-cli/arduino-cli-0.2.0-alpha.preview-linux32.tar.bz2)
+- [Linux ARM 0.2.0-alpha.preview](http://downloads.arduino.cc/arduino-cli/arduino-cli-0.2.0-alpha.preview-linuxarm.tar.bz2)
+- [Windows 0.2.0-alpha.preview](http://downloads.arduino.cc/arduino-cli/arduino-cli-0.2.0-alpha.preview-windows.zip)
+- [Mac OSX 0.2.0-alpha.preview](http://downloads.arduino.cc/arduino-cli/arduino-cli-0.2.0-alpha.preview-osx.zip)
+
+### Build the latest "bleeding-edge" from source
 
 * You should have a recent Go compiler installed.
 * Run `go get -u github.com/arduino/arduino-cli`