Although Facebook pages have a uniform look and layout, it's possible to embed custom HTML code into your Facebook page for a customized feel. On Facebook, the Static FBML app is Facebook's official and only way to customize a page with HTML. FBML (Facebook Markup Language) is Facebook's own proprietary, modified version of HTML, and the app also allows HTML code. With the FBML app, any user can use HTML to enhance your page.
Log in to your Facebook account. Go to your page where you want to embed HTML code.
Click the "Edit Page" button in the top-right corner. On the next page, click "Apps" in the left menu.
Click "Browse more applications," located below the list of "Added Apps" in the center. In the App search box in the left menu, type "FBML," and press "Enter."
Select the "Static FBML" app from the list of results. On the app info page, click "Go to App." The "Request for Permission" page subsequently appears.
Click "Allow." From the drop-down menu, select your page. Click "Done."
Go back to your Facebook page. Click "Edit Page" on the top-right of the page. Click "Apps" in the left menu. In the list of "Added Apps," the "Static FBML" app will appear.
Click "Go to App."
Enter your desired "Box Title" in the top box. This will be the title for the tab that appears for your FBML app in the left menu.
Enter your HTML code in the lower box entitled "FBML." Nearly all HTML tags are accepted here, so customize to your heart's content. Click "Save Changes" when complete.
Go back to your Facebook page. In the left menu, you'll notice a link with the same title you entered previously. Click this link. You have now embedded HTML on your Facebook page.
Facebook also allow FBML code to be used within the FBML app. Check the Facebook Help Center for more information on FBML tags.