Horde - Horde Groupware is a free, enterprise ready, browser based collaboration suite.
Conga Contracts - Conga Contracts is management solution designed to accelerate and simplify contract negotiations in Salesforce.
Roundcube - Web-based IMAP email client
Concord - Contract Management Software and unlimited Electronic Signatures. Reduce costs, maximize compliance & mitigate risk. Enterprise solutions available.
Mailo - Mailo is an email client where you can send and receive emails to and from anyone with an email address.
CobbleStone Software - Managing contracts just got easier with CobbleStone!