I have been tinkering with NodeMCU devkit boards recently. The easiest way to program these little beasts is to use arduino platform and install the compilers and other tools from . Unfortunately the stock arduino shipped with ubuntu 14.04 is quite old. You need a recent version of arduino software. to get the esp8266 board working.
Here is what I did.
Removed the existing arduio installation
$ sudo apt-get remove arduino
Download the appropriate arduino software from arduino.cc. This is available for both 32 bit and 64 bit editions. Choose the correct version.
The arduino software platfrom is written in Java. So install java runtime.
$ sudo apt-get install openjdk-7-jre
Unzip the arduino software and move it to an appropriate location. I moved it to /opt.
tar -xJf arduino-1.6.4-linux64.tar.xz
sudo mv arduino-1.6.4 /opt
Add appropriate path to .bashrc file.
I added PATH=$PATH;/opt/arduino-1.6.4/bin. Change it according to your arduino location and version.
Open a terminal and execute the new arduino.