Yes, both Zendesk Explore and GitHub offer a Free Trial.
Zendesk Explore is designed for Large Enterprises, Medium Business and Small Business.
GitHub is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Pricing for Zendesk Explore Starts at $49/User/Month whereas for GitHub Starts at $4/User/Month.
Some top alternatives to Zendesk Explore includes Evidence, Databox, ManageEngine Analytics Plus, Metric.ai, Dundas BI, SAS Business Intelligence, SAP BusinessObjects BI, Panintelligence, ibi Analytics Platform and myDATA3.
Some top alternatives to GitHub includes LiveCode, Codeanywhere, Visual Studio IDE, CodeinCloud, GitLive, Microsoft Azure, GitLab, CodeSee and Bitbucket.