Feng Office - Feng Office is a commercial Open Source web based solution aimed to enhance collaboration and productivity
Podio - Podio is the online work platform. Manage, share, and get your work done smarter together with tools that work like you. Free for 10 Users.
LibreOffice - Free office suite, open source, and compatible with .doc, .docx, .xls, .xlsx, .ppt, .pptx files. Updated regularly – download for free. Originally based on OpenOffice.org.
Notion - All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
Redmine - Flexible project management web application
MS SharePoint - Share, organize, and discover information with Microsoft SharePoint. Learn about SharePoint Online, OneDrive for Business, and Apps for SharePoint