Yes, both Jira Service Desk and GitHub offer a Free Trial.
Jira Service Desk is designed for Large Enterprises, Medium Business and Small Business.
GitHub is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Pricing for Jira Service Desk Starts at $10One-Time Payment whereas for GitHub Starts at $4/User/Month.
Some top alternatives to Jira Service Desk includes Freshservice, ManageEngine ServiceDesk Plus, SolarWinds Service Desk, Mint Service Desk, Symantec ServiceDesk, Freshdesk, HelpDesk, ReadyDesk, Milldesk, HESK, Scopedesk and GLPI.
Some top alternatives to GitHub includes LiveCode, Codeanywhere, Visual Studio IDE, CodeinCloud, GitLive, Microsoft Azure, GitLab, CodeSee and Bitbucket.