Sitecore - Sitecore A/S has produced the Sitecore content management system since 1999.
productboard - Beautiful and powerful product management.
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
ProdPad - ProdPad helps your team gather ideas, surface the best ones and turn them into product specs, and then put it all on a product roadmap.
Salesforce Service Cloud - Service Cloud integrates customer service with social networks and provides a self-service customer portal and knowledge base system.
ProductPlan - Cloud-based product roadmap software solution