Salesforce Service Cloud - Service Cloud integrates customer service with social networks and provides a self-service customer portal and knowledge base system.
Parakeet - Cloud-based phone system with mobile app, designed for teams
Zoho Desk - Industry's first context-aware Helpdesk Software
Convoso - Call center solution to covert leads faster
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
8x8 Cloud Contact Center - 8x8 Cloud Contact Center is a VoIP call center solution.