Dotstorming is a free online application for collaboration and group brainstorming in real-time. Create new board, invite people, and start a chat session.

Symu.co is a website to upload your project and collaborate with clients. You and clients can add comments anywhere on project. Provides revision history.

Tribecube is a free online collaboration service which has group chat, private chat, video call, file sharing and screen sharing features all in one.

Humhub is a free website to create private social network and collaborate with users. Works locally by setting up on your own local server.

Intellinote is an online collaboration tool which lets you make notes and assign tasks with your colleagues and friends.

Panmind is a free online collaboration tool that provides 5 GB free storage space. It helps to create projects and post web documents, files to projects.

Slack is a free online collaboration tool for members of any team so that they can interact with each other in real time and track the progress of project.

Framebench is an online document collaboration website, using which you can collaborate files of any type, and work in real-time with colleagues and bosses.

Groupiful is a free online collaboration service to work together in groups. Create events, notes, assign tasks to members, and upload files to your group.