Yes, both KBPublisher and Slite offer a Free Trial.
KBPublisher is designed for Large Enterprises, Medium Business and Small Business.
Slite is designed for Freelancers, Medium Business and Small Business.
Pricing for KBPublisher Starts at $19/Month when Billed Yearly whereas for Slite Starts at $6.67/User/Month when Billed Yearly.
Some top alternatives to KBPublisher includes Zoho Wiki, SmartSupport, KnowledgeBase Manager Pro, Omnistar Kbase, Talisma KnowledgeBase, IntelligenceBank KM, Microsoft Azure, KnowledgeOwl, KnowledgeBase and ProProfs Knowledge Base.
Some top alternatives to Slite includes Confluence, Notion, GitBook, Zoho Wiki, Drupal Wiki, LearnLode Enterprise, TWiki, Teamemo, Wiki Valley and Team Wiki.
