Made it a chrome extension for an easier install.

https://chrome.google.com/webstore/detail/textpad/edopaieiod...

Thanks, works like a charm.

Looking at the steam registry link[1] posted by Breakthrough, it looks like there is a mention of osx in the app.

[1] http://cdr.xpaw.ru/app/70/

Edit: I opened Steam on my mac, Half-Life is showing up under "Mac games," I'm downloading it now. Great.