Yes, both ZenHub and GitHub offer a Free Trial.
ZenHub is designed for Large Enterprises, Medium Business and Small Business.
GitHub is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Pricing for ZenHub Starts at $7.95/User/Month when Billed Yearly whereas for GitHub Starts at $4/User/Month.
Some top alternatives to ZenHub includes ClickUp, Smartsheet, Miro, Process Street, Wrike, Notion, HubSpot CRM, Jira, Trello, Asana, Teamwork, Kanbanize, Trackboard, Quick Base, Zenkit Projects, Height, Yodiz and Worktez.
Some top alternatives to GitHub includes LiveCode, Codeanywhere, Visual Studio IDE, CodeinCloud, GitLive, Microsoft Azure, GitLab, CodeSee and Bitbucket.