1. Web Mail
    1. Squirrelmail
    2. IMP
    3. RoundCube
    4. IlohaMail
    5. HastyMail
  2. client side GPG
    1. hushmail libraries
    2. gpg javascript
    3. gpg java
  3. Communications Servers
    1. Zimbra
    2. Hula
    3. scalix
    4. Citadel

This page is just an overview free software mail and messaging projects.

Web Mail

Squirrelmail

The standard. Very easy to install, works well, has lots of plugins which can make it do all kinds of crazy things. Stable. PHP. squirrelmail.org

IMP

Difficult to install, now has more features than squirrelmail. Some people prefer the IMP interface to squirrelmail. PHP. horde.org

RoundCube

AJAX fancy and slick. PHP. Still beta. Very pretty. roundcube.net

IlohaMail

I haven't tried it, but it claims to be easy to set up. Has contact groups, which SM and IMP don't have yet (in a usable way, at least). blog.ilohamail.org

HastyMail

Clean, fast, CSS, PHP. hastymail.sourceforge.net

client side GPG

hushmail libraries

Some hushmail">www.hushmail.com/about-downloads">hushmail java libraries are available for download. They do client side gpg, I believe.

gpg javascript

Someone wrote a javascript">www.hanewin.net/encrypt">javascript library to do gpg encryption and decryption entirely in javascript.

gpg java

There are a couple different libraries. Here is an example of a mysite.mweb.co.za/residents/c.meijer/mmusing.htm client">java gpg enabled client

Communications Servers

Zimbra

Monolith java communication server. AJAX. Outlook replacement plus gmail tags, etc. Fancy. Beta. www.zimbra.com/

Hula

Does everything. Calendering and mail server, used to be novell NetMail? Big and scalable. hula-project.org

scalix

tagline: "Enterprise-class Email & Calendaring on Linux. Web client. Desktop performance."
scalix.org. started life as HP's OpenMail. they have a open source 'community edition' which doesn't have some features, like multi-server support.

Citadel

Roots as a bbs. Many features, many UIs. Unique feature is that it has a 'room' concept, great for community sites. www.citadel.org