Yes, both GitHub and Commented offer a Free Trial.
GitHub is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Commented is designed for Large Enterprises, Small Business and Medium Business.
Pricing for GitHub Starts at $4/User/Month whereas for Commented Starts at $7.40per month when Billed Yearly.
Some top alternatives to GitHub includes LiveCode, Codeanywhere, Visual Studio IDE, CodeinCloud, GitLive, Microsoft Azure, GitLab, CodeSee and Bitbucket.
Some top alternatives to Commented includes and undefined.