Jitbit Helpdesk is a web-based help desk software it tracks support tickets, fully integrates with mailbox.

Vtiger CRM is online customer relationship management software that helps you track and nurture customers across marketing, sales, and customer service.

Kayako is a customer service software.

Helprace is a customer service software suite linking a ticket system with help desk software.

Trakdesk is a fully customizable customer support platform with all the bells and whistles you would need to provide exceptional customer support.

LiveChat is an online customer service software with live support, help desk software, and web analytics capabilities.

Brimir is an Open source ticket manager.