1. Retrospectiva
Retrospectiva is a powerful open-source project management tool, designed towards agile software development teams. It features a solid core with ticket system, code review and milestones, but it also has powerful addons like wiki, blog or agile project management.
2. Trac
Trac is one powerful issue tracking tool judging by the fact that Wordpress development is tracked using it. Trac is an enhanced open-source wiki and issue tracking system for software development projects. It uses a minimalistic approach to web-based software project management.
3. Collabtive
Collabtive is web-based open source project management software. It was developed as an PHP&Javascript alternative to commercial project management tools like Basecamp. It features basic project management features and it has a decent and usable user interface.
http://collabtive.o-dyn.de/index.php
4. Teambox
Although it is a rather new player in the project management area, Teambox can be seen as one of the future leaders. It is developed as an open source application and it benefits from a simple and clean user interface similar to Twitter. It supports multiple projects, statuses, document attachments.
5. Redmine
Redmine is a great project management tool based on Ruby on Rails and released under GPL v2. It has multiple projects support, news, documents & files management, time tracking and even multilingual support.
6. SteberPM
Continuing the open source trend, we will place SteberPM in this list. Teams can easily setup projects and keep track of tasks, issues, bugs, efforts etc – using SteberPM.
7. Todoyu
This application has a more compact yet visually rich interface compared to previous project management tools. Todoyu features are: manage multiple projects, overview your customer’s data, assign tasks, share files, group calendars and meet deadlines.
http://www.todoyu.com/en/todoyu/
8. OpenAtrium
With one impressive set of features as well as a clean and well executed user interface, OpenAtrium will definitely succeed against commercial tools. It is still in beta and probably when it will be stable, OpenAtrium will make happy a lot of teams.
9. PlanCake
Probably light is the term that comes into my mind when I see the user interface from PlanCake. It is super light and clean and it provides fast response to your actions. And considering that the project is free, it can make a lot of friends in freelancers.
10. myTinyTodo
I’ve left this application at the end because it is one of my favorites. Not because of its features but because of the simplicity and speed. myTinyTodo is as the name says a tiny todo list. The best thing about it is that you are quite productive using it and it serves its purpose: todo manager for individuals and freelancers.
