I am needing to deploy some web-based collaboration software for an NGO that does humanitarian work. Here are some of the software packages I have looked at and am considering: Zimbra phpGroupWare eGroupWare more.groupware Simple Groupware Here is a list of requirements: Needs to be able to run on secure HTTPS Needs to have a webmail client (can be simply a client that accesses POP, SMTP, or IMAP) Open source Preferably PHP and MySQL-based, but that is very much negotiable Needs to have a quality file sharing manager Preferably with a rich text editor that can edit MS Word DOCs Preferably something that is very easy to use and organize Something that can easily share the files among all the users Preferably has a shared calendar system What would you recommend I get?