Yes, both Zendesk Support and Salesforce Service Cloud offer a Free Trial.
Zendesk Support is designed for Large Enterprises, Medium Business and Small Business.
Salesforce Service Cloud is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Zendesk Support Starts at $19/user/month when yearly whereas for Salesforce Service Cloud Starts at $25/user/month when yearly.
Some top alternatives to Zendesk Support includes Zoho Desk, ManageEngine ServiceDesk Plus, Deskero, Support Hub, HelpDesk, Desky, Help Scout, Salesforce Service Cloud, ReadyDesk, Sitehelpdesk, HESK and BoldDesk.
Some top alternatives to Salesforce Service Cloud includes Zoho Desk, Zendesk Support, ManageEngine ServiceDesk Plus, Freshservice, Freshdesk, LiveAgent, HelpDesk, SysAid, Jitbit Helpdesk, HubSpot Service Hub, Help Scout, UseDesk, LabiDesk, AzureDesk, HESK and BoldDesk.