So yeah, I'm an avid Tf2 player, and ever since I new about custom maps in Tf2 I wanted to design and make my own map. Sadly, I'm on a Mac, so Source SDK wasn't available to my platform till last year, but I only knew about it around 2 weeks ago. Now, I still haven't completely installed Source SDK because I'm still not sure how to. Do I really need Github to install it? because Github is only available to OS X 10.7 or better(Lion and Mountain Lion) and I only have 10.6.8(Snow Leopard). What can I do? Thanks in advance.