Kayako, a good CRM software, which able to handles large amount of customer tickets, perform live chats with online customers. Established in 2001, Kayako builds the world’s leading helpdesk and customer engagement solutions which help organizations deliver better customer support.
Currently, more than 30,000 organizations of all sizes and from all industries including some of the world’s most respected brands like MSI, NASA, Sony, GE trust Kayako to power their support and provide an unbeatable customer service experience.
Their software are reasonable, check out this pricing from their website.
Server requirement :
PHP 5.3 and above, MySQL 5.0 and above, Zend Optimizer or Ion Cube optimizer (both are free) and any webserver supports php.