osTicket is a widely-used open source support ticket system. It seamlessly integrates inquiries created via email and web-based forms into a simple easy to use multi-user web interface. Easily manage, organize and archive all your support requests and responses in one place while providing your clients with accountability and responsiveness they deserve.

Hesk is Free PHP Help Desk Software that runs with a MySQL database. It allows you to setup a web based ticket support system (helpdesk) for your website. Once the Help Desk Software is installed your customers will be able to submit support tickets and staff will have an easy-to-use web interface to manage customer support requests.

Mibew Messenger is an open-source live support application written in PHP and MySQL. It enables one-on-one chat assistance in real-time directly from your website. You should place the button of Web Messenger at your site. Your visitors click the button and chat with your operators who help them.

Live helper chat is Free & Flexible & Open source - Live Support chat for your website. Web and desktop clients. XMPP notifications, GTalk, Jabber, OpenFire, Chrome extension, Node.js support, MySQL, PostgreSQL.

Vision Helpdesk offers customer service solutions for every size business, It offers three customer support solutions
1. Help Desk Software : Multi channel customer support ticketing help desk that allows you to manage various channels like E-MAIL, WEB-FORMS, TWITTER, FACEBOOK, CHATS, CALLS everything under single roof.
2. Satellite / Multi Company Help Desk : Manage your multiple brands or different companies customer support at centralized place, Setup different customer portal for each brand. Manage staff in different timezones and offer global customer support.
3. IT Service Desk : Service Desk software is enterprise level IT Help Desk that includes features from Help Desk and Satellite Help Desk additionally it offers ITIL / ITSM Modules - Incident, Problem, Change, Release, Contract, Financial Management, Service and Product Catalog, Vendor Management and more..
You will need a Valid License key to install and run Vision Helpdesk.

Sales Syntax Live Help (CSLH) is an open source live support solution that helps customer support with live help functionality that can be proactively pushed to visitors to your site or requested by the consumer. Sales Syntax includes a large range of features to allow multiple operators, multiple departments and multiple languages to be used. Sales Syntax Live Help is free and is progammed in PHP with Mysql for the datatabase. Other highlighted features include the ability to create your own questions, auto inviting visitors, referer tracking, page tracking, ability to view what the customer is typing as they type, multiple chat sessions, sound alert, leave a message if offline, push urls, quick responses, Customizable graphics, and multiple operators.

Faveo Helpdesk Open source ticketing system build on Laravel framework. Faveo word is derived from Latin which means to be favourable. Which truly highlights vision and the scope as well as the functionality of the product that Faveo is. It is specifically designed to cater the needs of startups and SME's empowering them with state of art, ticket based support system. In today's competitive startup scenario customer retention is one of the major challenges. Handling client query diligently is all the difference between retaining or losing a long lasting relationship.

HelpDeskZ is a FREE and Open Source help desk solution for your business. It is easily integrated to your site and support requests can be created via email or web-based forms. It will give you a friendly interface for your site's tickets management. You can create a wide knowledge base for your customers and with the opportunity to create Canned Responses for the most popular requests, your will improve your support sytem productivity. In resume, powerful, easy to use, reliable, open source and FREE.

OpenSupports is an open source ticket system for giving support to your clients. It provides you with a better management of your users inquiries. The software has tools to manage the tickets, like departments, staff members, custom responses, multi-language support.

phpMyFAQ is an open source FAQ system using PHP. phpMyFAQ is a multilingual, completely database-driven FAQ-system. It supports various databases to store all data, PHP 5.3.3 (or higher) is needed in order to access this data. phpMyFAQ also offers a multi-language Content Management-System with a WYSIWYG editor and an Image Manager, flexible multi-user support with user and group based permissions on categories and records, a wiki-like revision feature, a news system, user-tracking, language modules, enhanced automatic content negotiation, templates, extensive XML-support, PDF-support, a backup-system, a dynamic site map, related articles, tagging, RSS feeds, built-in spam protection systems, LDAP support, Twitter and Facebook support and an easy to use installation script.

Maian Support is a FREE support ticket system written in PHP/MySQL. Maian Support is a software with no nag screens, ads or spyware. It can be used for an unlimited time at no further cost. Support is an integral part of any business and good support helps you to build a solid relationship between you and your clients. Maian Support helps you to build this confidence by providing an easy to use support system completely free of charge.

FreeScout is the super lightweight free open source help desk and shared inbox written in PHP7 (Laravel 5.5 framework).

UVdesk community helpdesk project skeleton packaged along with the bare essential utilities and tools to build and customize your own helpdesk solutions.

HelpDEZk is a powerfull software that manages requests/incidents. It has all the needed requirements to an efficient workflow management of all processes involved in service execution. This control is done for internal demands and also for outsourced services. HelpDEZk can be used at any company's area, serving as an support to the shared service center concept, beyond the ability to log all the processes and maintain the request's history, it can pass it through many approval levels. HelpDEZk can put together advanced managing resources with an extremely easy use. Simple and intuitive screens make the day-by-day easier for your team, speeding up the procedures and saving up a lot of time. It is developped in objects oriented PHP language, with the MVC architecture and uses the templates system SMARTY. For the javascripts, JQUERY is used.

Attendize is an Open-source ticket selling and event management platform and is everything you need for a successful event. Attendize has a wide array of features aimed at making organising events as effortless as possible.

Handesk is a powerful yet simple Ticketing system, a system that allows to have multiple teams, with multiple users, easy and efficient reporting by all/team/user as well as lead management.