Yes, both GitHub and osTicket offer a Free Trial.
GitHub is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
osTicket is designed for Individuals, Large Enterprises, Medium Business and Small Business.
Pricing for GitHub Starts at $4/User/Month whereas for osTicket Starts at $9/User/Month.
Some top alternatives to GitHub includes LiveCode, Codeanywhere, Visual Studio IDE, CodeinCloud, GitLive, Microsoft Azure, GitLab, CodeSee and Bitbucket.
Some top alternatives to osTicket includes Zendesk Support, Zoho Desk, Tidio Helpdesk, Freshservice, Jira Service Desk, Freshdesk, HelpDesk, SysAid, UVdesk, Jitbit Helpdesk, eStreamDesk, ReadyDesk, Spiceworks Help Desk, HESK, BoldDesk and GLPI.