Today, we are listing here 19 Most Essential and useful open source applications that you probably want to know to use in your daily life. Most of them are top of the list projects that have an open source industry leading popularity and many of them are not listed here but over all the list has variety of projects for every one of you. Just take a look at them and share your thoughts here.

You are welcome to share if you know about any other open source project which our readers may like.

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23 Free And Online Web Based Applications Specially If You Are Designer Or Developer

21 Online Free Web Based Applications That You Probably Would Love To Use Every Day!

WordPress – Blog Tool and Weblog Platform

WordPress is a state-of-the-art publishing platform with a focus on aesthetics, web standards, and usability. WordPress is both free and priceless at the same time.

ModSecurity – Open Source Web Application Firewall

ModSecurity is a web application firewall that can work either embedded or as a reverse proxy. It provides protection from a range of attacks against web applications and allows for HTTP traffic monitoring, logging and real-time analysis. It is also an open source project that aims to make the web application firewall technology available to everyone.

SteelBlue Open Source Web Application Server

SteelBlue is an open-source Web application server environment in which Web-database applications can be developed completely in an extended HTML language. Similar to ColdFusion and Story Server, session and user-associated data as well as SQL commands can be directly embedded into the HTML page. Therefore, no CGI programming experience is required to develop applications with SteelBlue, only knowledge of SQL and HTML.

Dolphin :: Smart Community Builder

YouTube, MySpace, Odeo, Flickr, Match and Facebook – all in one, customizable and under your full control. You’re limited only by your imagination – not by software. Dolphin Smart Community Builder is a universal, free, open source software that allows you to build any kind of online community. With a huge variety of features & options, you can quickly develop your very unique and successful website.

PURE Unobtrusive Rendering Engine For HTML

PURE is an Open Source JavaScript Template Engine for HTML. Truly unobtrusive, it leaves your HTML untouched. It is cross-browser (IE 6.0+, FF 2+, Safari 2.0+, Opera 9.0+).

Bugzilla – Mozilla’s bug tracking system

Bugzilla is a bug tracking system designed to help teams manage software development. Hundreds of organizations across the globe are using this powerful tool to get organized and communicate effectively.

Mindquarry DO – Free Open Source Software Download for Team Collaboration

Mindquarry DO is an Open Source collaborative software platform for file sharing, task management, team collaboration and Wiki editing that is available for Windows, Linux and Mac OS X. Mindquarry runs as a web application with an optional desktop client for Windows, Linux and Mac OS that allows for desktop synchronization and offline work. As a result, you are able to connect with team members and share information from wherever you are, effectively improving team-work and increasing productivity within your team.

EPIWARE – A Open Source Document Management System

Epiware GPL project and document management, for those that like to be on the cutting edge of development. Take control of your information and content today.

jobberBase – The Open Source Job Board Software

jobberBase is a great open source job board software for anyone. You can get online your job posting website with jobberBase. It’s easy to install and configure to start your job board.

Flex SDK

Flex is a highly productive, open source framework for building and maintaining expressive web applications that deploy consistently on all major browsers, desktops and operating systems.

Open source Ticket Request System

OTRS is an O pen source T icket R equest S ystem (also well known as trouble ticket system) with many features to manage customer telephone calls and e-mails. The system is built to allow your support, sales, pre-sales, billing, internal IT, helpdesk, etc. department to react quickly to inbound inquiries. Do you receive many e-mails and want to answer them with a team of agents? You’re going to love the OTRS!

phpMyVisites Free Web Statistics And Analytics

phpMyVisites is a free and powerful open source (GNU/GPL) software for websites statistics and audience measurements. phpMyVisites gives a lot of information on websites visitors, visited pages, software/hardware utilization, etc… The GUI Interface is fun and practical. The installation is entirely automated and very simple.

LimeSurvey – The Leading Open Source Survey Tool

LimeSurvey (formerly PHPSurveyor) is an Open Source PHP web application to develop, publish and collect responses to online & offline surveys.

dotproject – Open Source Project and Task Management Software

The original theme flagged dotProject as an open source alternative to Microsoft products and other expensive, commercial applications. Right from the start, dotProject had, as it’s core aims a number of simple requirements which are Clean, simple and consistent user interface; Project Management functionality – not another CMS, groupware environment or all things to all people collaboration tool, but a project management environment; Open source and free usage.

The Freeway Project

Freeway is the most advanced Open Source eCommerce platform and Freeway offers selling methods only previously available in enterprise class or niche bespoke systems. Without having to purchase a commercial system and then paying a developer to build a custom installation, Freeway does what you need out of the box. Of course Freeway is great for selling products but it also sells events AND services AND subscriptions. From appointments and time based bookings to event ticketing and subscriptions Freeway is the eCommerce platform.

AtMail Open – Redefining Open Source Webmail

AtMail is an open source webmail client written in PHP. We aim to provide a elegant Ajax webmail client for existing IMAP mailservers, with less bloat and a focus on an intuitive, simple user interface.

OpenOffice – The Free and Open Productivity Suite

OpenOffice is the leading open-source office software suite for word processing, spreadsheets, presentations, graphics, databases and more. It is available in many languages and works on all common computers. It stores all your data in an international open standard format and can also read and write files from other common office software packages. It can be downloaded and used completely free of charge for any purpose.

Open Workbench – Open Source Project Management and Project Scheduling for Windows

Open Workbench is an open source Windows-based desktop application that provides robust project scheduling and management functionality and is free to distribute throughout the enterprise.

The SeaMonkey Project

The SeaMonkey project is a community effort to develop the SeaMonkey all-in-one internet application suite (see below). Such a software suite was previously made popular by Netscape and Mozilla, and the SeaMonkey project continues to develop and deliver high-quality updates to this concept. Containing an Internet browser, email & newsgroup client, HTML editor, IRC chat and web development tools, SeaMonkey is sure to appeal to advanced users, web developers and corporate users.

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