Cloud9 Instructions

In a workspace:

1. Click Cloud9, then Preferences (or use keyboard shortcut CTRL + ,)
2. Go to Themes, then click on You can also style Cloud9 by editing your stylesheet (this will open a blank styles.css file in the C9 editor)
3. Copy & paste the following:

@font-face{
    font-family: 'Fira Code';
    src: url('https://raw.githubusercontent.com/tonsky/FiraCode/5.2/distr/woff2/FiraCode-Regular.woff2') format('woff2'),
         url('https://raw.githubusercontent.com/tonsky/FiraCode/5.2/distr/woff/FiraCode-Regular.woff') format('woff'),
         url('https://raw.githubusercontent.com/tonsky/FiraCode/5.2/distr/ttf/FiraCode-Regular.ttf') format('truetype');
    font-weight: normal;
    font-style: normal;
}

.ace_editor{
    -webkit-font-feature-settings: "liga" on, "calt" on;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
    font-family: 'Fira Code';
}

4. Back in Preferences tab, click on User Settings, then click on Code Editor (Ace)
5. In Font Family field, enter Fira Code
6. Optionally, repeat step 5 for Preferences > User Settings > Terminal, if you want Fira Code font in C9 terminal.