Yes, both Green Pen and KnowledgeBase offer a Free Trial.
Green Pen is designed for Large Enterprises, Medium Business and Small Business.
KnowledgeBase is designed for Large Enterprises, Medium Business and Small Business.
The starting price of KnowledgeBase begins at $59/Month, while pricing details for Green Pen are unavailable.
Some top alternatives to Green Pen includes Red Pen, SmartSupport, SABIO, KnowledgeAQ, Qualified, Richdesk, Workvivo, KnowledgeBase, Whatis, Typed, ProProfs Knowledge Base and IFTTT.
Some top alternatives to KnowledgeBase includes KBPublisher, SmartSupport, KnowledgeBase Manager Pro, Omnistar Kbase, Talisma KnowledgeBase, IntelligenceBank KM, Helpjuice, KnowledgeOwl, Qualified, Workvivo, PaceKB and ProProfs Knowledge Base.