Serving Unity3D game through web

I've been assigned the task to serve a Unity3d game in my website (designed by someone else). They're flexible on serving the game directly from the website as they don't know if it s possible, so in the case that due to X issues it can't be possible I could provide a link (download a player?) to play the game externally. I've been digging through the Unity docs and found out the Unity Webplayer is only compatible with Opera, Safari and older versions of Firefox/I. Usually I'd dig into the matter and come up with a solution eventually but due to the time constraint I feel hard pressed to ask for advice from people who have already jumped these hoops.

Is there an alternative to the Unity Webplayer, does Unity provide some sort of quick, lightweight install for the game to which I can point users to from the website?

I should add that the game will be a lightweight, resource-inexpensive game.

I'm open to any and all suggestions however creative!

The app will most probably use the Rails framework for the web app.