GitHub has always branded itself as a "social collaboration platform" rather than anything else (well, first "git hosting" but secondly the social stuff).

Here is a early version of their landing page from 2008 (the year they launched): https://web.archive.org/web/20081111061111/http://github.com...

Notice the logo says "Social code hosting" and the messaging of the page is mostly around popular repositories, collaborative features and other social elements.