OK, so I sacrificed myself to check out their claims. Turns out the real list is a fair bit shorter than the advertised one:
∘ PHP Development Stack with Apache, PHP, MySQL, phpMyAdmin and Composer preinstalled.
∘ Node.js Development Stack with nvm, npm, Redis and MySQL server.
∘ Ruby Development Stack with RVM and Ruby on Rails preinstalled.
∘ Python Development Stack with pip and virtualenv preinstalled.
∘ C/C++ Development Stack with gcc & g++ compiler and gdb preinstalled.
∘ HTML5 Development Stack with Apache, npm, yeoman, bower and grunt preinstalled.