Kolab offers enterprise collaboration that differentiates itself by being more scalable, heterogeneous and secure. Unlike other solutions which merely aim to replace Microsoft Exchange but reinforce your dependency upon Microsoft Outlook and Windows, Kolab has an offer that goes far beyond that. As a true Free Software / Open Source solution with Open Standards from the interface to the storage layer, Kolab provides you with more client options than any other solution.
Your choices include the native Kolab Client based on KDE Kontact for Windows, Mac OS X or GNU/Linux for full groupware functionality, the Mozilla Suite with Thunderbird & Lightning for “groupware light” on the same platforms, Microsoft Outlook on Windows, a wide variety of mobile phones, and a web frontend based upon Roundcube, which was repeatedly ranked the world's No 1 AJAX based webmailer. Your choices also include the world's only touch screen full groupware client, Kontact Touch, on devices such as the Vivaldi Tablet.
Windows or Linux? The Kolab Client!
Or on the web? The Kolab Web Client, based on the world's best Free Software web mailer.
Or Mozilla Thunderbird & Lightning on Windows, Mac OS, Linux... take your pick.