In Unicode 7.0 there will be tons of Emoji icons added. Linux currently by default, is poorly supporting showing those chars. If you want to add them into your system, what should you do?
First, go to http://getemoji.com/ see what you can see for now.
There are some fonts or packages you need to download and install, for starters, this font is very useful. For Fedora user, install this package:
sudo yum install gdouros-symbola-fonts
This will enable the basic sets of the Emoji icons. Actually there are a lot more in Unicode 7.0, if you want to use them early, you need to download the font file.
Unzip the zip file, move the Symbola*.ttf files to ~/.fonts and then do the following command:
mkfontscale; fc-cache -fv
Refresh your firefox page and test it out! ✌